linux/fs/ceph/mds_client.c
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   1#include <linux/ceph/ceph_debug.h>
   2
   3#include <linux/fs.h>
   4#include <linux/wait.h>
   5#include <linux/slab.h>
   6#include <linux/sched.h>
   7#include <linux/debugfs.h>
   8#include <linux/seq_file.h>
   9
  10#include "super.h"
  11#include "mds_client.h"
  12
  13#include <linux/ceph/ceph_features.h>
  14#include <linux/ceph/messenger.h>
  15#include <linux/ceph/decode.h>
  16#include <linux/ceph/pagelist.h>
  17#include <linux/ceph/auth.h>
  18#include <linux/ceph/debugfs.h>
  19
  20/*
  21 * A cluster of MDS (metadata server) daemons is responsible for
  22 * managing the file system namespace (the directory hierarchy and
  23 * inodes) and for coordinating shared access to storage.  Metadata is
  24 * partitioning hierarchically across a number of servers, and that
  25 * partition varies over time as the cluster adjusts the distribution
  26 * in order to balance load.
  27 *
  28 * The MDS client is primarily responsible to managing synchronous
  29 * metadata requests for operations like open, unlink, and so forth.
  30 * If there is a MDS failure, we find out about it when we (possibly
  31 * request and) receive a new MDS map, and can resubmit affected
  32 * requests.
  33 *
  34 * For the most part, though, we take advantage of a lossless
  35 * communications channel to the MDS, and do not need to worry about
  36 * timing out or resubmitting requests.
  37 *
  38 * We maintain a stateful "session" with each MDS we interact with.
  39 * Within each session, we sent periodic heartbeat messages to ensure
  40 * any capabilities or leases we have been issues remain valid.  If
  41 * the session times out and goes stale, our leases and capabilities
  42 * are no longer valid.
  43 */
  44
  45struct ceph_reconnect_state {
  46        struct ceph_pagelist *pagelist;
  47        bool flock;
  48};
  49
  50static void __wake_requests(struct ceph_mds_client *mdsc,
  51                            struct list_head *head);
  52
  53static const struct ceph_connection_operations mds_con_ops;
  54
  55
  56/*
  57 * mds reply parsing
  58 */
  59
  60/*
  61 * parse individual inode info
  62 */
  63static int parse_reply_info_in(void **p, void *end,
  64                               struct ceph_mds_reply_info_in *info,
  65                               int features)
  66{
  67        int err = -EIO;
  68
  69        info->in = *p;
  70        *p += sizeof(struct ceph_mds_reply_inode) +
  71                sizeof(*info->in->fragtree.splits) *
  72                le32_to_cpu(info->in->fragtree.nsplits);
  73
  74        ceph_decode_32_safe(p, end, info->symlink_len, bad);
  75        ceph_decode_need(p, end, info->symlink_len, bad);
  76        info->symlink = *p;
  77        *p += info->symlink_len;
  78
  79        if (features & CEPH_FEATURE_DIRLAYOUTHASH)
  80                ceph_decode_copy_safe(p, end, &info->dir_layout,
  81                                      sizeof(info->dir_layout), bad);
  82        else
  83                memset(&info->dir_layout, 0, sizeof(info->dir_layout));
  84
  85        ceph_decode_32_safe(p, end, info->xattr_len, bad);
  86        ceph_decode_need(p, end, info->xattr_len, bad);
  87        info->xattr_data = *p;
  88        *p += info->xattr_len;
  89        return 0;
  90bad:
  91        return err;
  92}
  93
  94/*
  95 * parse a normal reply, which may contain a (dir+)dentry and/or a
  96 * target inode.
  97 */
  98static int parse_reply_info_trace(void **p, void *end,
  99                                  struct ceph_mds_reply_info_parsed *info,
 100                                  int features)
 101{
 102        int err;
 103
 104        if (info->head->is_dentry) {
 105                err = parse_reply_info_in(p, end, &info->diri, features);
 106                if (err < 0)
 107                        goto out_bad;
 108
 109                if (unlikely(*p + sizeof(*info->dirfrag) > end))
 110                        goto bad;
 111                info->dirfrag = *p;
 112                *p += sizeof(*info->dirfrag) +
 113                        sizeof(u32)*le32_to_cpu(info->dirfrag->ndist);
 114                if (unlikely(*p > end))
 115                        goto bad;
 116
 117                ceph_decode_32_safe(p, end, info->dname_len, bad);
 118                ceph_decode_need(p, end, info->dname_len, bad);
 119                info->dname = *p;
 120                *p += info->dname_len;
 121                info->dlease = *p;
 122                *p += sizeof(*info->dlease);
 123        }
 124
 125        if (info->head->is_target) {
 126                err = parse_reply_info_in(p, end, &info->targeti, features);
 127                if (err < 0)
 128                        goto out_bad;
 129        }
 130
 131        if (unlikely(*p != end))
 132                goto bad;
 133        return 0;
 134
 135bad:
 136        err = -EIO;
 137out_bad:
 138        pr_err("problem parsing mds trace %d\n", err);
 139        return err;
 140}
 141
 142/*
 143 * parse readdir results
 144 */
 145static int parse_reply_info_dir(void **p, void *end,
 146                                struct ceph_mds_reply_info_parsed *info,
 147                                int features)
 148{
 149        u32 num, i = 0;
 150        int err;
 151
 152        info->dir_dir = *p;
 153        if (*p + sizeof(*info->dir_dir) > end)
 154                goto bad;
 155        *p += sizeof(*info->dir_dir) +
 156                sizeof(u32)*le32_to_cpu(info->dir_dir->ndist);
 157        if (*p > end)
 158                goto bad;
 159
 160        ceph_decode_need(p, end, sizeof(num) + 2, bad);
 161        num = ceph_decode_32(p);
 162        info->dir_end = ceph_decode_8(p);
 163        info->dir_complete = ceph_decode_8(p);
 164        if (num == 0)
 165                goto done;
 166
 167        /* alloc large array */
 168        info->dir_nr = num;
 169        info->dir_in = kcalloc(num, sizeof(*info->dir_in) +
 170                               sizeof(*info->dir_dname) +
 171                               sizeof(*info->dir_dname_len) +
 172                               sizeof(*info->dir_dlease),
 173                               GFP_NOFS);
 174        if (info->dir_in == NULL) {
 175                err = -ENOMEM;
 176                goto out_bad;
 177        }
 178        info->dir_dname = (void *)(info->dir_in + num);
 179        info->dir_dname_len = (void *)(info->dir_dname + num);
 180        info->dir_dlease = (void *)(info->dir_dname_len + num);
 181
 182        while (num) {
 183                /* dentry */
 184                ceph_decode_need(p, end, sizeof(u32)*2, bad);
 185                info->dir_dname_len[i] = ceph_decode_32(p);
 186                ceph_decode_need(p, end, info->dir_dname_len[i], bad);
 187                info->dir_dname[i] = *p;
 188                *p += info->dir_dname_len[i];
 189                dout("parsed dir dname '%.*s'\n", info->dir_dname_len[i],
 190                     info->dir_dname[i]);
 191                info->dir_dlease[i] = *p;
 192                *p += sizeof(struct ceph_mds_reply_lease);
 193
 194                /* inode */
 195                err = parse_reply_info_in(p, end, &info->dir_in[i], features);
 196                if (err < 0)
 197                        goto out_bad;
 198                i++;
 199                num--;
 200        }
 201
 202done:
 203        if (*p != end)
 204                goto bad;
 205        return 0;
 206
 207bad:
 208        err = -EIO;
 209out_bad:
 210        pr_err("problem parsing dir contents %d\n", err);
 211        return err;
 212}
 213
 214/*
 215 * parse fcntl F_GETLK results
 216 */
 217static int parse_reply_info_filelock(void **p, void *end,
 218                                     struct ceph_mds_reply_info_parsed *info,
 219                                     int features)
 220{
 221        if (*p + sizeof(*info->filelock_reply) > end)
 222                goto bad;
 223
 224        info->filelock_reply = *p;
 225        *p += sizeof(*info->filelock_reply);
 226
 227        if (unlikely(*p != end))
 228                goto bad;
 229        return 0;
 230
 231bad:
 232        return -EIO;
 233}
 234
 235/*
 236 * parse create results
 237 */
 238static int parse_reply_info_create(void **p, void *end,
 239                                  struct ceph_mds_reply_info_parsed *info,
 240                                  int features)
 241{
 242        if (features & CEPH_FEATURE_REPLY_CREATE_INODE) {
 243                if (*p == end) {
 244                        info->has_create_ino = false;
 245                } else {
 246                        info->has_create_ino = true;
 247                        info->ino = ceph_decode_64(p);
 248                }
 249        }
 250
 251        if (unlikely(*p != end))
 252                goto bad;
 253        return 0;
 254
 255bad:
 256        return -EIO;
 257}
 258
 259/*
 260 * parse extra results
 261 */
 262static int parse_reply_info_extra(void **p, void *end,
 263                                  struct ceph_mds_reply_info_parsed *info,
 264                                  int features)
 265{
 266        if (info->head->op == CEPH_MDS_OP_GETFILELOCK)
 267                return parse_reply_info_filelock(p, end, info, features);
 268        else if (info->head->op == CEPH_MDS_OP_READDIR ||
 269                 info->head->op == CEPH_MDS_OP_LSSNAP)
 270                return parse_reply_info_dir(p, end, info, features);
 271        else if (info->head->op == CEPH_MDS_OP_CREATE)
 272                return parse_reply_info_create(p, end, info, features);
 273        else
 274                return -EIO;
 275}
 276
 277/*
 278 * parse entire mds reply
 279 */
 280static int parse_reply_info(struct ceph_msg *msg,
 281                            struct ceph_mds_reply_info_parsed *info,
 282                            int features)
 283{
 284        void *p, *end;
 285        u32 len;
 286        int err;
 287
 288        info->head = msg->front.iov_base;
 289        p = msg->front.iov_base + sizeof(struct ceph_mds_reply_head);
 290        end = p + msg->front.iov_len - sizeof(struct ceph_mds_reply_head);
 291
 292        /* trace */
 293        ceph_decode_32_safe(&p, end, len, bad);
 294        if (len > 0) {
 295                ceph_decode_need(&p, end, len, bad);
 296                err = parse_reply_info_trace(&p, p+len, info, features);
 297                if (err < 0)
 298                        goto out_bad;
 299        }
 300
 301        /* extra */
 302        ceph_decode_32_safe(&p, end, len, bad);
 303        if (len > 0) {
 304                ceph_decode_need(&p, end, len, bad);
 305                err = parse_reply_info_extra(&p, p+len, info, features);
 306                if (err < 0)
 307                        goto out_bad;
 308        }
 309
 310        /* snap blob */
 311        ceph_decode_32_safe(&p, end, len, bad);
 312        info->snapblob_len = len;
 313        info->snapblob = p;
 314        p += len;
 315
 316        if (p != end)
 317                goto bad;
 318        return 0;
 319
 320bad:
 321        err = -EIO;
 322out_bad:
 323        pr_err("mds parse_reply err %d\n", err);
 324        return err;
 325}
 326
 327static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 328{
 329        kfree(info->dir_in);
 330}
 331
 332
 333/*
 334 * sessions
 335 */
 336static const char *session_state_name(int s)
 337{
 338        switch (s) {
 339        case CEPH_MDS_SESSION_NEW: return "new";
 340        case CEPH_MDS_SESSION_OPENING: return "opening";
 341        case CEPH_MDS_SESSION_OPEN: return "open";
 342        case CEPH_MDS_SESSION_HUNG: return "hung";
 343        case CEPH_MDS_SESSION_CLOSING: return "closing";
 344        case CEPH_MDS_SESSION_RESTARTING: return "restarting";
 345        case CEPH_MDS_SESSION_RECONNECTING: return "reconnecting";
 346        default: return "???";
 347        }
 348}
 349
 350static struct ceph_mds_session *get_session(struct ceph_mds_session *s)
 351{
 352        if (atomic_inc_not_zero(&s->s_ref)) {
 353                dout("mdsc get_session %p %d -> %d\n", s,
 354                     atomic_read(&s->s_ref)-1, atomic_read(&s->s_ref));
 355                return s;
 356        } else {
 357                dout("mdsc get_session %p 0 -- FAIL", s);
 358                return NULL;
 359        }
 360}
 361
 362void ceph_put_mds_session(struct ceph_mds_session *s)
 363{
 364        dout("mdsc put_session %p %d -> %d\n", s,
 365             atomic_read(&s->s_ref), atomic_read(&s->s_ref)-1);
 366        if (atomic_dec_and_test(&s->s_ref)) {
 367                if (s->s_auth.authorizer)
 368                        ceph_auth_destroy_authorizer(
 369                                s->s_mdsc->fsc->client->monc.auth,
 370                                s->s_auth.authorizer);
 371                kfree(s);
 372        }
 373}
 374
 375/*
 376 * called under mdsc->mutex
 377 */
 378struct ceph_mds_session *__ceph_lookup_mds_session(struct ceph_mds_client *mdsc,
 379                                                   int mds)
 380{
 381        struct ceph_mds_session *session;
 382
 383        if (mds >= mdsc->max_sessions || mdsc->sessions[mds] == NULL)
 384                return NULL;
 385        session = mdsc->sessions[mds];
 386        dout("lookup_mds_session %p %d\n", session,
 387             atomic_read(&session->s_ref));
 388        get_session(session);
 389        return session;
 390}
 391
 392static bool __have_session(struct ceph_mds_client *mdsc, int mds)
 393{
 394        if (mds >= mdsc->max_sessions)
 395                return false;
 396        return mdsc->sessions[mds];
 397}
 398
 399static int __verify_registered_session(struct ceph_mds_client *mdsc,
 400                                       struct ceph_mds_session *s)
 401{
 402        if (s->s_mds >= mdsc->max_sessions ||
 403            mdsc->sessions[s->s_mds] != s)
 404                return -ENOENT;
 405        return 0;
 406}
 407
 408/*
 409 * create+register a new session for given mds.
 410 * called under mdsc->mutex.
 411 */
 412static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 413                                                 int mds)
 414{
 415        struct ceph_mds_session *s;
 416
 417        s = kzalloc(sizeof(*s), GFP_NOFS);
 418        if (!s)
 419                return ERR_PTR(-ENOMEM);
 420        s->s_mdsc = mdsc;
 421        s->s_mds = mds;
 422        s->s_state = CEPH_MDS_SESSION_NEW;
 423        s->s_ttl = 0;
 424        s->s_seq = 0;
 425        mutex_init(&s->s_mutex);
 426
 427        ceph_con_init(&s->s_con, s, &mds_con_ops, &mdsc->fsc->client->msgr);
 428
 429        spin_lock_init(&s->s_gen_ttl_lock);
 430        s->s_cap_gen = 0;
 431        s->s_cap_ttl = jiffies - 1;
 432
 433        spin_lock_init(&s->s_cap_lock);
 434        s->s_renew_requested = 0;
 435        s->s_renew_seq = 0;
 436        INIT_LIST_HEAD(&s->s_caps);
 437        s->s_nr_caps = 0;
 438        s->s_trim_caps = 0;
 439        atomic_set(&s->s_ref, 1);
 440        INIT_LIST_HEAD(&s->s_waiting);
 441        INIT_LIST_HEAD(&s->s_unsafe);
 442        s->s_num_cap_releases = 0;
 443        s->s_cap_iterator = NULL;
 444        INIT_LIST_HEAD(&s->s_cap_releases);
 445        INIT_LIST_HEAD(&s->s_cap_releases_done);
 446        INIT_LIST_HEAD(&s->s_cap_flushing);
 447        INIT_LIST_HEAD(&s->s_cap_snaps_flushing);
 448
 449        dout("register_session mds%d\n", mds);
 450        if (mds >= mdsc->max_sessions) {
 451                int newmax = 1 << get_count_order(mds+1);
 452                struct ceph_mds_session **sa;
 453
 454                dout("register_session realloc to %d\n", newmax);
 455                sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
 456                if (sa == NULL)
 457                        goto fail_realloc;
 458                if (mdsc->sessions) {
 459                        memcpy(sa, mdsc->sessions,
 460                               mdsc->max_sessions * sizeof(void *));
 461                        kfree(mdsc->sessions);
 462                }
 463                mdsc->sessions = sa;
 464                mdsc->max_sessions = newmax;
 465        }
 466        mdsc->sessions[mds] = s;
 467        atomic_inc(&s->s_ref);  /* one ref to sessions[], one to caller */
 468
 469        ceph_con_open(&s->s_con, CEPH_ENTITY_TYPE_MDS, mds,
 470                      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
 471
 472        return s;
 473
 474fail_realloc:
 475        kfree(s);
 476        return ERR_PTR(-ENOMEM);
 477}
 478
 479/*
 480 * called under mdsc->mutex
 481 */
 482static void __unregister_session(struct ceph_mds_client *mdsc,
 483                               struct ceph_mds_session *s)
 484{
 485        dout("__unregister_session mds%d %p\n", s->s_mds, s);
 486        BUG_ON(mdsc->sessions[s->s_mds] != s);
 487        mdsc->sessions[s->s_mds] = NULL;
 488        ceph_con_close(&s->s_con);
 489        ceph_put_mds_session(s);
 490}
 491
 492/*
 493 * drop session refs in request.
 494 *
 495 * should be last request ref, or hold mdsc->mutex
 496 */
 497static void put_request_session(struct ceph_mds_request *req)
 498{
 499        if (req->r_session) {
 500                ceph_put_mds_session(req->r_session);
 501                req->r_session = NULL;
 502        }
 503}
 504
 505void ceph_mdsc_release_request(struct kref *kref)
 506{
 507        struct ceph_mds_request *req = container_of(kref,
 508                                                    struct ceph_mds_request,
 509                                                    r_kref);
 510        if (req->r_request)
 511                ceph_msg_put(req->r_request);
 512        if (req->r_reply) {
 513                ceph_msg_put(req->r_reply);
 514                destroy_reply_info(&req->r_reply_info);
 515        }
 516        if (req->r_inode) {
 517                ceph_put_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
 518                iput(req->r_inode);
 519        }
 520        if (req->r_locked_dir)
 521                ceph_put_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
 522        if (req->r_target_inode)
 523                iput(req->r_target_inode);
 524        if (req->r_dentry)
 525                dput(req->r_dentry);
 526        if (req->r_old_dentry) {
 527                /*
 528                 * track (and drop pins for) r_old_dentry_dir
 529                 * separately, since r_old_dentry's d_parent may have
 530                 * changed between the dir mutex being dropped and
 531                 * this request being freed.
 532                 */
 533                ceph_put_cap_refs(ceph_inode(req->r_old_dentry_dir),
 534                                  CEPH_CAP_PIN);
 535                dput(req->r_old_dentry);
 536                iput(req->r_old_dentry_dir);
 537        }
 538        kfree(req->r_path1);
 539        kfree(req->r_path2);
 540        put_request_session(req);
 541        ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
 542        kfree(req);
 543}
 544
 545/*
 546 * lookup session, bump ref if found.
 547 *
 548 * called under mdsc->mutex.
 549 */
 550static struct ceph_mds_request *__lookup_request(struct ceph_mds_client *mdsc,
 551                                             u64 tid)
 552{
 553        struct ceph_mds_request *req;
 554        struct rb_node *n = mdsc->request_tree.rb_node;
 555
 556        while (n) {
 557                req = rb_entry(n, struct ceph_mds_request, r_node);
 558                if (tid < req->r_tid)
 559                        n = n->rb_left;
 560                else if (tid > req->r_tid)
 561                        n = n->rb_right;
 562                else {
 563                        ceph_mdsc_get_request(req);
 564                        return req;
 565                }
 566        }
 567        return NULL;
 568}
 569
 570static void __insert_request(struct ceph_mds_client *mdsc,
 571                             struct ceph_mds_request *new)
 572{
 573        struct rb_node **p = &mdsc->request_tree.rb_node;
 574        struct rb_node *parent = NULL;
 575        struct ceph_mds_request *req = NULL;
 576
 577        while (*p) {
 578                parent = *p;
 579                req = rb_entry(parent, struct ceph_mds_request, r_node);
 580                if (new->r_tid < req->r_tid)
 581                        p = &(*p)->rb_left;
 582                else if (new->r_tid > req->r_tid)
 583                        p = &(*p)->rb_right;
 584                else
 585                        BUG();
 586        }
 587
 588        rb_link_node(&new->r_node, parent, p);
 589        rb_insert_color(&new->r_node, &mdsc->request_tree);
 590}
 591
 592/*
 593 * Register an in-flight request, and assign a tid.  Link to directory
 594 * are modifying (if any).
 595 *
 596 * Called under mdsc->mutex.
 597 */
 598static void __register_request(struct ceph_mds_client *mdsc,
 599                               struct ceph_mds_request *req,
 600                               struct inode *dir)
 601{
 602        req->r_tid = ++mdsc->last_tid;
 603        if (req->r_num_caps)
 604                ceph_reserve_caps(mdsc, &req->r_caps_reservation,
 605                                  req->r_num_caps);
 606        dout("__register_request %p tid %lld\n", req, req->r_tid);
 607        ceph_mdsc_get_request(req);
 608        __insert_request(mdsc, req);
 609
 610        req->r_uid = current_fsuid();
 611        req->r_gid = current_fsgid();
 612
 613        if (dir) {
 614                struct ceph_inode_info *ci = ceph_inode(dir);
 615
 616                ihold(dir);
 617                spin_lock(&ci->i_unsafe_lock);
 618                req->r_unsafe_dir = dir;
 619                list_add_tail(&req->r_unsafe_dir_item, &ci->i_unsafe_dirops);
 620                spin_unlock(&ci->i_unsafe_lock);
 621        }
 622}
 623
 624static void __unregister_request(struct ceph_mds_client *mdsc,
 625                                 struct ceph_mds_request *req)
 626{
 627        dout("__unregister_request %p tid %lld\n", req, req->r_tid);
 628        rb_erase(&req->r_node, &mdsc->request_tree);
 629        RB_CLEAR_NODE(&req->r_node);
 630
 631        if (req->r_unsafe_dir) {
 632                struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
 633
 634                spin_lock(&ci->i_unsafe_lock);
 635                list_del_init(&req->r_unsafe_dir_item);
 636                spin_unlock(&ci->i_unsafe_lock);
 637
 638                iput(req->r_unsafe_dir);
 639                req->r_unsafe_dir = NULL;
 640        }
 641
 642        ceph_mdsc_put_request(req);
 643}
 644
 645/*
 646 * Choose mds to send request to next.  If there is a hint set in the
 647 * request (e.g., due to a prior forward hint from the mds), use that.
 648 * Otherwise, consult frag tree and/or caps to identify the
 649 * appropriate mds.  If all else fails, choose randomly.
 650 *
 651 * Called under mdsc->mutex.
 652 */
 653static struct dentry *get_nonsnap_parent(struct dentry *dentry)
 654{
 655        /*
 656         * we don't need to worry about protecting the d_parent access
 657         * here because we never renaming inside the snapped namespace
 658         * except to resplice to another snapdir, and either the old or new
 659         * result is a valid result.
 660         */
 661        while (!IS_ROOT(dentry) && ceph_snap(dentry->d_inode) != CEPH_NOSNAP)
 662                dentry = dentry->d_parent;
 663        return dentry;
 664}
 665
 666static int __choose_mds(struct ceph_mds_client *mdsc,
 667                        struct ceph_mds_request *req)
 668{
 669        struct inode *inode;
 670        struct ceph_inode_info *ci;
 671        struct ceph_cap *cap;
 672        int mode = req->r_direct_mode;
 673        int mds = -1;
 674        u32 hash = req->r_direct_hash;
 675        bool is_hash = req->r_direct_is_hash;
 676
 677        /*
 678         * is there a specific mds we should try?  ignore hint if we have
 679         * no session and the mds is not up (active or recovering).
 680         */
 681        if (req->r_resend_mds >= 0 &&
 682            (__have_session(mdsc, req->r_resend_mds) ||
 683             ceph_mdsmap_get_state(mdsc->mdsmap, req->r_resend_mds) > 0)) {
 684                dout("choose_mds using resend_mds mds%d\n",
 685                     req->r_resend_mds);
 686                return req->r_resend_mds;
 687        }
 688
 689        if (mode == USE_RANDOM_MDS)
 690                goto random;
 691
 692        inode = NULL;
 693        if (req->r_inode) {
 694                inode = req->r_inode;
 695        } else if (req->r_dentry) {
 696                /* ignore race with rename; old or new d_parent is okay */
 697                struct dentry *parent = req->r_dentry->d_parent;
 698                struct inode *dir = parent->d_inode;
 699
 700                if (dir->i_sb != mdsc->fsc->sb) {
 701                        /* not this fs! */
 702                        inode = req->r_dentry->d_inode;
 703                } else if (ceph_snap(dir) != CEPH_NOSNAP) {
 704                        /* direct snapped/virtual snapdir requests
 705                         * based on parent dir inode */
 706                        struct dentry *dn = get_nonsnap_parent(parent);
 707                        inode = dn->d_inode;
 708                        dout("__choose_mds using nonsnap parent %p\n", inode);
 709                } else if (req->r_dentry->d_inode) {
 710                        /* dentry target */
 711                        inode = req->r_dentry->d_inode;
 712                } else {
 713                        /* dir + name */
 714                        inode = dir;
 715                        hash = ceph_dentry_hash(dir, req->r_dentry);
 716                        is_hash = true;
 717                }
 718        }
 719
 720        dout("__choose_mds %p is_hash=%d (%d) mode %d\n", inode, (int)is_hash,
 721             (int)hash, mode);
 722        if (!inode)
 723                goto random;
 724        ci = ceph_inode(inode);
 725
 726        if (is_hash && S_ISDIR(inode->i_mode)) {
 727                struct ceph_inode_frag frag;
 728                int found;
 729
 730                ceph_choose_frag(ci, hash, &frag, &found);
 731                if (found) {
 732                        if (mode == USE_ANY_MDS && frag.ndist > 0) {
 733                                u8 r;
 734
 735                                /* choose a random replica */
 736                                get_random_bytes(&r, 1);
 737                                r %= frag.ndist;
 738                                mds = frag.dist[r];
 739                                dout("choose_mds %p %llx.%llx "
 740                                     "frag %u mds%d (%d/%d)\n",
 741                                     inode, ceph_vinop(inode),
 742                                     frag.frag, mds,
 743                                     (int)r, frag.ndist);
 744                                if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 745                                    CEPH_MDS_STATE_ACTIVE)
 746                                        return mds;
 747                        }
 748
 749                        /* since this file/dir wasn't known to be
 750                         * replicated, then we want to look for the
 751                         * authoritative mds. */
 752                        mode = USE_AUTH_MDS;
 753                        if (frag.mds >= 0) {
 754                                /* choose auth mds */
 755                                mds = frag.mds;
 756                                dout("choose_mds %p %llx.%llx "
 757                                     "frag %u mds%d (auth)\n",
 758                                     inode, ceph_vinop(inode), frag.frag, mds);
 759                                if (ceph_mdsmap_get_state(mdsc->mdsmap, mds) >=
 760                                    CEPH_MDS_STATE_ACTIVE)
 761                                        return mds;
 762                        }
 763                }
 764        }
 765
 766        spin_lock(&ci->i_ceph_lock);
 767        cap = NULL;
 768        if (mode == USE_AUTH_MDS)
 769                cap = ci->i_auth_cap;
 770        if (!cap && !RB_EMPTY_ROOT(&ci->i_caps))
 771                cap = rb_entry(rb_first(&ci->i_caps), struct ceph_cap, ci_node);
 772        if (!cap) {
 773                spin_unlock(&ci->i_ceph_lock);
 774                goto random;
 775        }
 776        mds = cap->session->s_mds;
 777        dout("choose_mds %p %llx.%llx mds%d (%scap %p)\n",
 778             inode, ceph_vinop(inode), mds,
 779             cap == ci->i_auth_cap ? "auth " : "", cap);
 780        spin_unlock(&ci->i_ceph_lock);
 781        return mds;
 782
 783random:
 784        mds = ceph_mdsmap_get_random_mds(mdsc->mdsmap);
 785        dout("choose_mds chose random mds%d\n", mds);
 786        return mds;
 787}
 788
 789
 790/*
 791 * session messages
 792 */
 793static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 794{
 795        struct ceph_msg *msg;
 796        struct ceph_mds_session_head *h;
 797
 798        msg = ceph_msg_new(CEPH_MSG_CLIENT_SESSION, sizeof(*h), GFP_NOFS,
 799                           false);
 800        if (!msg) {
 801                pr_err("create_session_msg ENOMEM creating msg\n");
 802                return NULL;
 803        }
 804        h = msg->front.iov_base;
 805        h->op = cpu_to_le32(op);
 806        h->seq = cpu_to_le64(seq);
 807        return msg;
 808}
 809
 810/*
 811 * send session open request.
 812 *
 813 * called under mdsc->mutex
 814 */
 815static int __open_session(struct ceph_mds_client *mdsc,
 816                          struct ceph_mds_session *session)
 817{
 818        struct ceph_msg *msg;
 819        int mstate;
 820        int mds = session->s_mds;
 821
 822        /* wait for mds to go active? */
 823        mstate = ceph_mdsmap_get_state(mdsc->mdsmap, mds);
 824        dout("open_session to mds%d (%s)\n", mds,
 825             ceph_mds_state_name(mstate));
 826        session->s_state = CEPH_MDS_SESSION_OPENING;
 827        session->s_renew_requested = jiffies;
 828
 829        /* send connect message */
 830        msg = create_session_msg(CEPH_SESSION_REQUEST_OPEN, session->s_seq);
 831        if (!msg)
 832                return -ENOMEM;
 833        ceph_con_send(&session->s_con, msg);
 834        return 0;
 835}
 836
 837/*
 838 * open sessions for any export targets for the given mds
 839 *
 840 * called under mdsc->mutex
 841 */
 842static void __open_export_target_sessions(struct ceph_mds_client *mdsc,
 843                                          struct ceph_mds_session *session)
 844{
 845        struct ceph_mds_info *mi;
 846        struct ceph_mds_session *ts;
 847        int i, mds = session->s_mds;
 848        int target;
 849
 850        if (mds >= mdsc->mdsmap->m_max_mds)
 851                return;
 852        mi = &mdsc->mdsmap->m_info[mds];
 853        dout("open_export_target_sessions for mds%d (%d targets)\n",
 854             session->s_mds, mi->num_export_targets);
 855
 856        for (i = 0; i < mi->num_export_targets; i++) {
 857                target = mi->export_targets[i];
 858                ts = __ceph_lookup_mds_session(mdsc, target);
 859                if (!ts) {
 860                        ts = register_session(mdsc, target);
 861                        if (IS_ERR(ts))
 862                                return;
 863                }
 864                if (session->s_state == CEPH_MDS_SESSION_NEW ||
 865                    session->s_state == CEPH_MDS_SESSION_CLOSING)
 866                        __open_session(mdsc, session);
 867                else
 868                        dout(" mds%d target mds%d %p is %s\n", session->s_mds,
 869                             i, ts, session_state_name(ts->s_state));
 870                ceph_put_mds_session(ts);
 871        }
 872}
 873
 874void ceph_mdsc_open_export_target_sessions(struct ceph_mds_client *mdsc,
 875                                           struct ceph_mds_session *session)
 876{
 877        mutex_lock(&mdsc->mutex);
 878        __open_export_target_sessions(mdsc, session);
 879        mutex_unlock(&mdsc->mutex);
 880}
 881
 882/*
 883 * session caps
 884 */
 885
 886/*
 887 * Free preallocated cap messages assigned to this session
 888 */
 889static void cleanup_cap_releases(struct ceph_mds_session *session)
 890{
 891        struct ceph_msg *msg;
 892
 893        spin_lock(&session->s_cap_lock);
 894        while (!list_empty(&session->s_cap_releases)) {
 895                msg = list_first_entry(&session->s_cap_releases,
 896                                       struct ceph_msg, list_head);
 897                list_del_init(&msg->list_head);
 898                ceph_msg_put(msg);
 899        }
 900        while (!list_empty(&session->s_cap_releases_done)) {
 901                msg = list_first_entry(&session->s_cap_releases_done,
 902                                       struct ceph_msg, list_head);
 903                list_del_init(&msg->list_head);
 904                ceph_msg_put(msg);
 905        }
 906        spin_unlock(&session->s_cap_lock);
 907}
 908
 909/*
 910 * Helper to safely iterate over all caps associated with a session, with
 911 * special care taken to handle a racing __ceph_remove_cap().
 912 *
 913 * Caller must hold session s_mutex.
 914 */
 915static int iterate_session_caps(struct ceph_mds_session *session,
 916                                 int (*cb)(struct inode *, struct ceph_cap *,
 917                                            void *), void *arg)
 918{
 919        struct list_head *p;
 920        struct ceph_cap *cap;
 921        struct inode *inode, *last_inode = NULL;
 922        struct ceph_cap *old_cap = NULL;
 923        int ret;
 924
 925        dout("iterate_session_caps %p mds%d\n", session, session->s_mds);
 926        spin_lock(&session->s_cap_lock);
 927        p = session->s_caps.next;
 928        while (p != &session->s_caps) {
 929                cap = list_entry(p, struct ceph_cap, session_caps);
 930                inode = igrab(&cap->ci->vfs_inode);
 931                if (!inode) {
 932                        p = p->next;
 933                        continue;
 934                }
 935                session->s_cap_iterator = cap;
 936                spin_unlock(&session->s_cap_lock);
 937
 938                if (last_inode) {
 939                        iput(last_inode);
 940                        last_inode = NULL;
 941                }
 942                if (old_cap) {
 943                        ceph_put_cap(session->s_mdsc, old_cap);
 944                        old_cap = NULL;
 945                }
 946
 947                ret = cb(inode, cap, arg);
 948                last_inode = inode;
 949
 950                spin_lock(&session->s_cap_lock);
 951                p = p->next;
 952                if (cap->ci == NULL) {
 953                        dout("iterate_session_caps  finishing cap %p removal\n",
 954                             cap);
 955                        BUG_ON(cap->session != session);
 956                        list_del_init(&cap->session_caps);
 957                        session->s_nr_caps--;
 958                        cap->session = NULL;
 959                        old_cap = cap;  /* put_cap it w/o locks held */
 960                }
 961                if (ret < 0)
 962                        goto out;
 963        }
 964        ret = 0;
 965out:
 966        session->s_cap_iterator = NULL;
 967        spin_unlock(&session->s_cap_lock);
 968
 969        if (last_inode)
 970                iput(last_inode);
 971        if (old_cap)
 972                ceph_put_cap(session->s_mdsc, old_cap);
 973
 974        return ret;
 975}
 976
 977static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
 978                                  void *arg)
 979{
 980        struct ceph_inode_info *ci = ceph_inode(inode);
 981        int drop = 0;
 982
 983        dout("removing cap %p, ci is %p, inode is %p\n",
 984             cap, ci, &ci->vfs_inode);
 985        spin_lock(&ci->i_ceph_lock);
 986        __ceph_remove_cap(cap);
 987        if (!__ceph_is_any_real_caps(ci)) {
 988                struct ceph_mds_client *mdsc =
 989                        ceph_sb_to_client(inode->i_sb)->mdsc;
 990
 991                spin_lock(&mdsc->cap_dirty_lock);
 992                if (!list_empty(&ci->i_dirty_item)) {
 993                        pr_info(" dropping dirty %s state for %p %lld\n",
 994                                ceph_cap_string(ci->i_dirty_caps),
 995                                inode, ceph_ino(inode));
 996                        ci->i_dirty_caps = 0;
 997                        list_del_init(&ci->i_dirty_item);
 998                        drop = 1;
 999                }
1000                if (!list_empty(&ci->i_flushing_item)) {
1001                        pr_info(" dropping dirty+flushing %s state for %p %lld\n",
1002                                ceph_cap_string(ci->i_flushing_caps),
1003                                inode, ceph_ino(inode));
1004                        ci->i_flushing_caps = 0;
1005                        list_del_init(&ci->i_flushing_item);
1006                        mdsc->num_cap_flushing--;
1007                        drop = 1;
1008                }
1009                if (drop && ci->i_wrbuffer_ref) {
1010                        pr_info(" dropping dirty data for %p %lld\n",
1011                                inode, ceph_ino(inode));
1012                        ci->i_wrbuffer_ref = 0;
1013                        ci->i_wrbuffer_ref_head = 0;
1014                        drop++;
1015                }
1016                spin_unlock(&mdsc->cap_dirty_lock);
1017        }
1018        spin_unlock(&ci->i_ceph_lock);
1019        while (drop--)
1020                iput(inode);
1021        return 0;
1022}
1023
1024/*
1025 * caller must hold session s_mutex
1026 */
1027static void remove_session_caps(struct ceph_mds_session *session)
1028{
1029        dout("remove_session_caps on %p\n", session);
1030        iterate_session_caps(session, remove_session_caps_cb, NULL);
1031        BUG_ON(session->s_nr_caps > 0);
1032        BUG_ON(!list_empty(&session->s_cap_flushing));
1033        cleanup_cap_releases(session);
1034}
1035
1036/*
1037 * wake up any threads waiting on this session's caps.  if the cap is
1038 * old (didn't get renewed on the client reconnect), remove it now.
1039 *
1040 * caller must hold s_mutex.
1041 */
1042static int wake_up_session_cb(struct inode *inode, struct ceph_cap *cap,
1043                              void *arg)
1044{
1045        struct ceph_inode_info *ci = ceph_inode(inode);
1046
1047        wake_up_all(&ci->i_cap_wq);
1048        if (arg) {
1049                spin_lock(&ci->i_ceph_lock);
1050                ci->i_wanted_max_size = 0;
1051                ci->i_requested_max_size = 0;
1052                spin_unlock(&ci->i_ceph_lock);
1053        }
1054        return 0;
1055}
1056
1057static void wake_up_session_caps(struct ceph_mds_session *session,
1058                                 int reconnect)
1059{
1060        dout("wake_up_session_caps %p mds%d\n", session, session->s_mds);
1061        iterate_session_caps(session, wake_up_session_cb,
1062                             (void *)(unsigned long)reconnect);
1063}
1064
1065/*
1066 * Send periodic message to MDS renewing all currently held caps.  The
1067 * ack will reset the expiration for all caps from this session.
1068 *
1069 * caller holds s_mutex
1070 */
1071static int send_renew_caps(struct ceph_mds_client *mdsc,
1072                           struct ceph_mds_session *session)
1073{
1074        struct ceph_msg *msg;
1075        int state;
1076
1077        if (time_after_eq(jiffies, session->s_cap_ttl) &&
1078            time_after_eq(session->s_cap_ttl, session->s_renew_requested))
1079                pr_info("mds%d caps stale\n", session->s_mds);
1080        session->s_renew_requested = jiffies;
1081
1082        /* do not try to renew caps until a recovering mds has reconnected
1083         * with its clients. */
1084        state = ceph_mdsmap_get_state(mdsc->mdsmap, session->s_mds);
1085        if (state < CEPH_MDS_STATE_RECONNECT) {
1086                dout("send_renew_caps ignoring mds%d (%s)\n",
1087                     session->s_mds, ceph_mds_state_name(state));
1088                return 0;
1089        }
1090
1091        dout("send_renew_caps to mds%d (%s)\n", session->s_mds,
1092                ceph_mds_state_name(state));
1093        msg = create_session_msg(CEPH_SESSION_REQUEST_RENEWCAPS,
1094                                 ++session->s_renew_seq);
1095        if (!msg)
1096                return -ENOMEM;
1097        ceph_con_send(&session->s_con, msg);
1098        return 0;
1099}
1100
1101/*
1102 * Note new cap ttl, and any transition from stale -> not stale (fresh?).
1103 *
1104 * Called under session->s_mutex
1105 */
1106static void renewed_caps(struct ceph_mds_client *mdsc,
1107                         struct ceph_mds_session *session, int is_renew)
1108{
1109        int was_stale;
1110        int wake = 0;
1111
1112        spin_lock(&session->s_cap_lock);
1113        was_stale = is_renew && time_after_eq(jiffies, session->s_cap_ttl);
1114
1115        session->s_cap_ttl = session->s_renew_requested +
1116                mdsc->mdsmap->m_session_timeout*HZ;
1117
1118        if (was_stale) {
1119                if (time_before(jiffies, session->s_cap_ttl)) {
1120                        pr_info("mds%d caps renewed\n", session->s_mds);
1121                        wake = 1;
1122                } else {
1123                        pr_info("mds%d caps still stale\n", session->s_mds);
1124                }
1125        }
1126        dout("renewed_caps mds%d ttl now %lu, was %s, now %s\n",
1127             session->s_mds, session->s_cap_ttl, was_stale ? "stale" : "fresh",
1128             time_before(jiffies, session->s_cap_ttl) ? "stale" : "fresh");
1129        spin_unlock(&session->s_cap_lock);
1130
1131        if (wake)
1132                wake_up_session_caps(session, 0);
1133}
1134
1135/*
1136 * send a session close request
1137 */
1138static int request_close_session(struct ceph_mds_client *mdsc,
1139                                 struct ceph_mds_session *session)
1140{
1141        struct ceph_msg *msg;
1142
1143        dout("request_close_session mds%d state %s seq %lld\n",
1144             session->s_mds, session_state_name(session->s_state),
1145             session->s_seq);
1146        msg = create_session_msg(CEPH_SESSION_REQUEST_CLOSE, session->s_seq);
1147        if (!msg)
1148                return -ENOMEM;
1149        ceph_con_send(&session->s_con, msg);
1150        return 0;
1151}
1152
1153/*
1154 * Called with s_mutex held.
1155 */
1156static int __close_session(struct ceph_mds_client *mdsc,
1157                         struct ceph_mds_session *session)
1158{
1159        if (session->s_state >= CEPH_MDS_SESSION_CLOSING)
1160                return 0;
1161        session->s_state = CEPH_MDS_SESSION_CLOSING;
1162        return request_close_session(mdsc, session);
1163}
1164
1165/*
1166 * Trim old(er) caps.
1167 *
1168 * Because we can't cache an inode without one or more caps, we do
1169 * this indirectly: if a cap is unused, we prune its aliases, at which
1170 * point the inode will hopefully get dropped to.
1171 *
1172 * Yes, this is a bit sloppy.  Our only real goal here is to respond to
1173 * memory pressure from the MDS, though, so it needn't be perfect.
1174 */
1175static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
1176{
1177        struct ceph_mds_session *session = arg;
1178        struct ceph_inode_info *ci = ceph_inode(inode);
1179        int used, oissued, mine;
1180
1181        if (session->s_trim_caps <= 0)
1182                return -1;
1183
1184        spin_lock(&ci->i_ceph_lock);
1185        mine = cap->issued | cap->implemented;
1186        used = __ceph_caps_used(ci);
1187        oissued = __ceph_caps_issued_other(ci, cap);
1188
1189        dout("trim_caps_cb %p cap %p mine %s oissued %s used %s\n",
1190             inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
1191             ceph_cap_string(used));
1192        if (ci->i_dirty_caps)
1193                goto out;   /* dirty caps */
1194        if ((used & ~oissued) & mine)
1195                goto out;   /* we need these caps */
1196
1197        session->s_trim_caps--;
1198        if (oissued) {
1199                /* we aren't the only cap.. just remove us */
1200                __queue_cap_release(session, ceph_ino(inode), cap->cap_id,
1201                                    cap->mseq, cap->issue_seq);
1202                __ceph_remove_cap(cap);
1203        } else {
1204                /* try to drop referring dentries */
1205                spin_unlock(&ci->i_ceph_lock);
1206                d_prune_aliases(inode);
1207                dout("trim_caps_cb %p cap %p  pruned, count now %d\n",
1208                     inode, cap, atomic_read(&inode->i_count));
1209                return 0;
1210        }
1211
1212out:
1213        spin_unlock(&ci->i_ceph_lock);
1214        return 0;
1215}
1216
1217/*
1218 * Trim session cap count down to some max number.
1219 */
1220static int trim_caps(struct ceph_mds_client *mdsc,
1221                     struct ceph_mds_session *session,
1222                     int max_caps)
1223{
1224        int trim_caps = session->s_nr_caps - max_caps;
1225
1226        dout("trim_caps mds%d start: %d / %d, trim %d\n",
1227             session->s_mds, session->s_nr_caps, max_caps, trim_caps);
1228        if (trim_caps > 0) {
1229                session->s_trim_caps = trim_caps;
1230                iterate_session_caps(session, trim_caps_cb, session);
1231                dout("trim_caps mds%d done: %d / %d, trimmed %d\n",
1232                     session->s_mds, session->s_nr_caps, max_caps,
1233                        trim_caps - session->s_trim_caps);
1234                session->s_trim_caps = 0;
1235        }
1236        return 0;
1237}
1238
1239/*
1240 * Allocate cap_release messages.  If there is a partially full message
1241 * in the queue, try to allocate enough to cover it's remainder, so that
1242 * we can send it immediately.
1243 *
1244 * Called under s_mutex.
1245 */
1246int ceph_add_cap_releases(struct ceph_mds_client *mdsc,
1247                          struct ceph_mds_session *session)
1248{
1249        struct ceph_msg *msg, *partial = NULL;
1250        struct ceph_mds_cap_release *head;
1251        int err = -ENOMEM;
1252        int extra = mdsc->fsc->mount_options->cap_release_safety;
1253        int num;
1254
1255        dout("add_cap_releases %p mds%d extra %d\n", session, session->s_mds,
1256             extra);
1257
1258        spin_lock(&session->s_cap_lock);
1259
1260        if (!list_empty(&session->s_cap_releases)) {
1261                msg = list_first_entry(&session->s_cap_releases,
1262                                       struct ceph_msg,
1263                                 list_head);
1264                head = msg->front.iov_base;
1265                num = le32_to_cpu(head->num);
1266                if (num) {
1267                        dout(" partial %p with (%d/%d)\n", msg, num,
1268                             (int)CEPH_CAPS_PER_RELEASE);
1269                        extra += CEPH_CAPS_PER_RELEASE - num;
1270                        partial = msg;
1271                }
1272        }
1273        while (session->s_num_cap_releases < session->s_nr_caps + extra) {
1274                spin_unlock(&session->s_cap_lock);
1275                msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPRELEASE, PAGE_CACHE_SIZE,
1276                                   GFP_NOFS, false);
1277                if (!msg)
1278                        goto out_unlocked;
1279                dout("add_cap_releases %p msg %p now %d\n", session, msg,
1280                     (int)msg->front.iov_len);
1281                head = msg->front.iov_base;
1282                head->num = cpu_to_le32(0);
1283                msg->front.iov_len = sizeof(*head);
1284                spin_lock(&session->s_cap_lock);
1285                list_add(&msg->list_head, &session->s_cap_releases);
1286                session->s_num_cap_releases += CEPH_CAPS_PER_RELEASE;
1287        }
1288
1289        if (partial) {
1290                head = partial->front.iov_base;
1291                num = le32_to_cpu(head->num);
1292                dout(" queueing partial %p with %d/%d\n", partial, num,
1293                     (int)CEPH_CAPS_PER_RELEASE);
1294                list_move_tail(&partial->list_head,
1295                               &session->s_cap_releases_done);
1296                session->s_num_cap_releases -= CEPH_CAPS_PER_RELEASE - num;
1297        }
1298        err = 0;
1299        spin_unlock(&session->s_cap_lock);
1300out_unlocked:
1301        return err;
1302}
1303
1304/*
1305 * flush all dirty inode data to disk.
1306 *
1307 * returns true if we've flushed through want_flush_seq
1308 */
1309static int check_cap_flush(struct ceph_mds_client *mdsc, u64 want_flush_seq)
1310{
1311        int mds, ret = 1;
1312
1313        dout("check_cap_flush want %lld\n", want_flush_seq);
1314        mutex_lock(&mdsc->mutex);
1315        for (mds = 0; ret && mds < mdsc->max_sessions; mds++) {
1316                struct ceph_mds_session *session = mdsc->sessions[mds];
1317
1318                if (!session)
1319                        continue;
1320                get_session(session);
1321                mutex_unlock(&mdsc->mutex);
1322
1323                mutex_lock(&session->s_mutex);
1324                if (!list_empty(&session->s_cap_flushing)) {
1325                        struct ceph_inode_info *ci =
1326                                list_entry(session->s_cap_flushing.next,
1327                                           struct ceph_inode_info,
1328                                           i_flushing_item);
1329                        struct inode *inode = &ci->vfs_inode;
1330
1331                        spin_lock(&ci->i_ceph_lock);
1332                        if (ci->i_cap_flush_seq <= want_flush_seq) {
1333                                dout("check_cap_flush still flushing %p "
1334                                     "seq %lld <= %lld to mds%d\n", inode,
1335                                     ci->i_cap_flush_seq, want_flush_seq,
1336                                     session->s_mds);
1337                                ret = 0;
1338                        }
1339                        spin_unlock(&ci->i_ceph_lock);
1340                }
1341                mutex_unlock(&session->s_mutex);
1342                ceph_put_mds_session(session);
1343
1344                if (!ret)
1345                        return ret;
1346                mutex_lock(&mdsc->mutex);
1347        }
1348
1349        mutex_unlock(&mdsc->mutex);
1350        dout("check_cap_flush ok, flushed thru %lld\n", want_flush_seq);
1351        return ret;
1352}
1353
1354/*
1355 * called under s_mutex
1356 */
1357void ceph_send_cap_releases(struct ceph_mds_client *mdsc,
1358                            struct ceph_mds_session *session)
1359{
1360        struct ceph_msg *msg;
1361
1362        dout("send_cap_releases mds%d\n", session->s_mds);
1363        spin_lock(&session->s_cap_lock);
1364        while (!list_empty(&session->s_cap_releases_done)) {
1365                msg = list_first_entry(&session->s_cap_releases_done,
1366                                 struct ceph_msg, list_head);
1367                list_del_init(&msg->list_head);
1368                spin_unlock(&session->s_cap_lock);
1369                msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1370                dout("send_cap_releases mds%d %p\n", session->s_mds, msg);
1371                ceph_con_send(&session->s_con, msg);
1372                spin_lock(&session->s_cap_lock);
1373        }
1374        spin_unlock(&session->s_cap_lock);
1375}
1376
1377static void discard_cap_releases(struct ceph_mds_client *mdsc,
1378                                 struct ceph_mds_session *session)
1379{
1380        struct ceph_msg *msg;
1381        struct ceph_mds_cap_release *head;
1382        unsigned num;
1383
1384        dout("discard_cap_releases mds%d\n", session->s_mds);
1385        spin_lock(&session->s_cap_lock);
1386
1387        /* zero out the in-progress message */
1388        msg = list_first_entry(&session->s_cap_releases,
1389                               struct ceph_msg, list_head);
1390        head = msg->front.iov_base;
1391        num = le32_to_cpu(head->num);
1392        dout("discard_cap_releases mds%d %p %u\n", session->s_mds, msg, num);
1393        head->num = cpu_to_le32(0);
1394        msg->front.iov_len = sizeof(*head);
1395        session->s_num_cap_releases += num;
1396
1397        /* requeue completed messages */
1398        while (!list_empty(&session->s_cap_releases_done)) {
1399                msg = list_first_entry(&session->s_cap_releases_done,
1400                                 struct ceph_msg, list_head);
1401                list_del_init(&msg->list_head);
1402
1403                head = msg->front.iov_base;
1404                num = le32_to_cpu(head->num);
1405                dout("discard_cap_releases mds%d %p %u\n", session->s_mds, msg,
1406                     num);
1407                session->s_num_cap_releases += num;
1408                head->num = cpu_to_le32(0);
1409                msg->front.iov_len = sizeof(*head);
1410                list_add(&msg->list_head, &session->s_cap_releases);
1411        }
1412
1413        spin_unlock(&session->s_cap_lock);
1414}
1415
1416/*
1417 * requests
1418 */
1419
1420/*
1421 * Create an mds request.
1422 */
1423struct ceph_mds_request *
1424ceph_mdsc_create_request(struct ceph_mds_client *mdsc, int op, int mode)
1425{
1426        struct ceph_mds_request *req = kzalloc(sizeof(*req), GFP_NOFS);
1427
1428        if (!req)
1429                return ERR_PTR(-ENOMEM);
1430
1431        mutex_init(&req->r_fill_mutex);
1432        req->r_mdsc = mdsc;
1433        req->r_started = jiffies;
1434        req->r_resend_mds = -1;
1435        INIT_LIST_HEAD(&req->r_unsafe_dir_item);
1436        req->r_fmode = -1;
1437        kref_init(&req->r_kref);
1438        INIT_LIST_HEAD(&req->r_wait);
1439        init_completion(&req->r_completion);
1440        init_completion(&req->r_safe_completion);
1441        INIT_LIST_HEAD(&req->r_unsafe_item);
1442
1443        req->r_op = op;
1444        req->r_direct_mode = mode;
1445        return req;
1446}
1447
1448/*
1449 * return oldest (lowest) request, tid in request tree, 0 if none.
1450 *
1451 * called under mdsc->mutex.
1452 */
1453static struct ceph_mds_request *__get_oldest_req(struct ceph_mds_client *mdsc)
1454{
1455        if (RB_EMPTY_ROOT(&mdsc->request_tree))
1456                return NULL;
1457        return rb_entry(rb_first(&mdsc->request_tree),
1458                        struct ceph_mds_request, r_node);
1459}
1460
1461static u64 __get_oldest_tid(struct ceph_mds_client *mdsc)
1462{
1463        struct ceph_mds_request *req = __get_oldest_req(mdsc);
1464
1465        if (req)
1466                return req->r_tid;
1467        return 0;
1468}
1469
1470/*
1471 * Build a dentry's path.  Allocate on heap; caller must kfree.  Based
1472 * on build_path_from_dentry in fs/cifs/dir.c.
1473 *
1474 * If @stop_on_nosnap, generate path relative to the first non-snapped
1475 * inode.
1476 *
1477 * Encode hidden .snap dirs as a double /, i.e.
1478 *   foo/.snap/bar -> foo//bar
1479 */
1480char *ceph_mdsc_build_path(struct dentry *dentry, int *plen, u64 *base,
1481                           int stop_on_nosnap)
1482{
1483        struct dentry *temp;
1484        char *path;
1485        int len, pos;
1486        unsigned seq;
1487
1488        if (dentry == NULL)
1489                return ERR_PTR(-EINVAL);
1490
1491retry:
1492        len = 0;
1493        seq = read_seqbegin(&rename_lock);
1494        rcu_read_lock();
1495        for (temp = dentry; !IS_ROOT(temp);) {
1496                struct inode *inode = temp->d_inode;
1497                if (inode && ceph_snap(inode) == CEPH_SNAPDIR)
1498                        len++;  /* slash only */
1499                else if (stop_on_nosnap && inode &&
1500                         ceph_snap(inode) == CEPH_NOSNAP)
1501                        break;
1502                else
1503                        len += 1 + temp->d_name.len;
1504                temp = temp->d_parent;
1505        }
1506        rcu_read_unlock();
1507        if (len)
1508                len--;  /* no leading '/' */
1509
1510        path = kmalloc(len+1, GFP_NOFS);
1511        if (path == NULL)
1512                return ERR_PTR(-ENOMEM);
1513        pos = len;
1514        path[pos] = 0;  /* trailing null */
1515        rcu_read_lock();
1516        for (temp = dentry; !IS_ROOT(temp) && pos != 0; ) {
1517                struct inode *inode;
1518
1519                spin_lock(&temp->d_lock);
1520                inode = temp->d_inode;
1521                if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
1522                        dout("build_path path+%d: %p SNAPDIR\n",
1523                             pos, temp);
1524                } else if (stop_on_nosnap && inode &&
1525                           ceph_snap(inode) == CEPH_NOSNAP) {
1526                        spin_unlock(&temp->d_lock);
1527                        break;
1528                } else {
1529                        pos -= temp->d_name.len;
1530                        if (pos < 0) {
1531                                spin_unlock(&temp->d_lock);
1532                                break;
1533                        }
1534                        strncpy(path + pos, temp->d_name.name,
1535                                temp->d_name.len);
1536                }
1537                spin_unlock(&temp->d_lock);
1538                if (pos)
1539                        path[--pos] = '/';
1540                temp = temp->d_parent;
1541        }
1542        rcu_read_unlock();
1543        if (pos != 0 || read_seqretry(&rename_lock, seq)) {
1544                pr_err("build_path did not end path lookup where "
1545                       "expected, namelen is %d, pos is %d\n", len, pos);
1546                /* presumably this is only possible if racing with a
1547                   rename of one of the parent directories (we can not
1548                   lock the dentries above us to prevent this, but
1549                   retrying should be harmless) */
1550                kfree(path);
1551                goto retry;
1552        }
1553
1554        *base = ceph_ino(temp->d_inode);
1555        *plen = len;
1556        dout("build_path on %p %d built %llx '%.*s'\n",
1557             dentry, d_count(dentry), *base, len, path);
1558        return path;
1559}
1560
1561static int build_dentry_path(struct dentry *dentry,
1562                             const char **ppath, int *ppathlen, u64 *pino,
1563                             int *pfreepath)
1564{
1565        char *path;
1566
1567        if (ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP) {
1568                *pino = ceph_ino(dentry->d_parent->d_inode);
1569                *ppath = dentry->d_name.name;
1570                *ppathlen = dentry->d_name.len;
1571                return 0;
1572        }
1573        path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1574        if (IS_ERR(path))
1575                return PTR_ERR(path);
1576        *ppath = path;
1577        *pfreepath = 1;
1578        return 0;
1579}
1580
1581static int build_inode_path(struct inode *inode,
1582                            const char **ppath, int *ppathlen, u64 *pino,
1583                            int *pfreepath)
1584{
1585        struct dentry *dentry;
1586        char *path;
1587
1588        if (ceph_snap(inode) == CEPH_NOSNAP) {
1589                *pino = ceph_ino(inode);
1590                *ppathlen = 0;
1591                return 0;
1592        }
1593        dentry = d_find_alias(inode);
1594        path = ceph_mdsc_build_path(dentry, ppathlen, pino, 1);
1595        dput(dentry);
1596        if (IS_ERR(path))
1597                return PTR_ERR(path);
1598        *ppath = path;
1599        *pfreepath = 1;
1600        return 0;
1601}
1602
1603/*
1604 * request arguments may be specified via an inode *, a dentry *, or
1605 * an explicit ino+path.
1606 */
1607static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
1608                                  const char *rpath, u64 rino,
1609                                  const char **ppath, int *pathlen,
1610                                  u64 *ino, int *freepath)
1611{
1612        int r = 0;
1613
1614        if (rinode) {
1615                r = build_inode_path(rinode, ppath, pathlen, ino, freepath);
1616                dout(" inode %p %llx.%llx\n", rinode, ceph_ino(rinode),
1617                     ceph_snap(rinode));
1618        } else if (rdentry) {
1619                r = build_dentry_path(rdentry, ppath, pathlen, ino, freepath);
1620                dout(" dentry %p %llx/%.*s\n", rdentry, *ino, *pathlen,
1621                     *ppath);
1622        } else if (rpath || rino) {
1623                *ino = rino;
1624                *ppath = rpath;
1625                *pathlen = rpath ? strlen(rpath) : 0;
1626                dout(" path %.*s\n", *pathlen, rpath);
1627        }
1628
1629        return r;
1630}
1631
1632/*
1633 * called under mdsc->mutex
1634 */
1635static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
1636                                               struct ceph_mds_request *req,
1637                                               int mds)
1638{
1639        struct ceph_msg *msg;
1640        struct ceph_mds_request_head *head;
1641        const char *path1 = NULL;
1642        const char *path2 = NULL;
1643        u64 ino1 = 0, ino2 = 0;
1644        int pathlen1 = 0, pathlen2 = 0;
1645        int freepath1 = 0, freepath2 = 0;
1646        int len;
1647        u16 releases;
1648        void *p, *end;
1649        int ret;
1650
1651        ret = set_request_path_attr(req->r_inode, req->r_dentry,
1652                              req->r_path1, req->r_ino1.ino,
1653                              &path1, &pathlen1, &ino1, &freepath1);
1654        if (ret < 0) {
1655                msg = ERR_PTR(ret);
1656                goto out;
1657        }
1658
1659        ret = set_request_path_attr(NULL, req->r_old_dentry,
1660                              req->r_path2, req->r_ino2.ino,
1661                              &path2, &pathlen2, &ino2, &freepath2);
1662        if (ret < 0) {
1663                msg = ERR_PTR(ret);
1664                goto out_free1;
1665        }
1666
1667        len = sizeof(*head) +
1668                pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64));
1669
1670        /* calculate (max) length for cap releases */
1671        len += sizeof(struct ceph_mds_request_release) *
1672                (!!req->r_inode_drop + !!req->r_dentry_drop +
1673                 !!req->r_old_inode_drop + !!req->r_old_dentry_drop);
1674        if (req->r_dentry_drop)
1675                len += req->r_dentry->d_name.len;
1676        if (req->r_old_dentry_drop)
1677                len += req->r_old_dentry->d_name.len;
1678
1679        msg = ceph_msg_new(CEPH_MSG_CLIENT_REQUEST, len, GFP_NOFS, false);
1680        if (!msg) {
1681                msg = ERR_PTR(-ENOMEM);
1682                goto out_free2;
1683        }
1684
1685        msg->hdr.tid = cpu_to_le64(req->r_tid);
1686
1687        head = msg->front.iov_base;
1688        p = msg->front.iov_base + sizeof(*head);
1689        end = msg->front.iov_base + msg->front.iov_len;
1690
1691        head->mdsmap_epoch = cpu_to_le32(mdsc->mdsmap->m_epoch);
1692        head->op = cpu_to_le32(req->r_op);
1693        head->caller_uid = cpu_to_le32(from_kuid(&init_user_ns, req->r_uid));
1694        head->caller_gid = cpu_to_le32(from_kgid(&init_user_ns, req->r_gid));
1695        head->args = req->r_args;
1696
1697        ceph_encode_filepath(&p, end, ino1, path1);
1698        ceph_encode_filepath(&p, end, ino2, path2);
1699
1700        /* make note of release offset, in case we need to replay */
1701        req->r_request_release_offset = p - msg->front.iov_base;
1702
1703        /* cap releases */
1704        releases = 0;
1705        if (req->r_inode_drop)
1706                releases += ceph_encode_inode_release(&p,
1707                      req->r_inode ? req->r_inode : req->r_dentry->d_inode,
1708                      mds, req->r_inode_drop, req->r_inode_unless, 0);
1709        if (req->r_dentry_drop)
1710                releases += ceph_encode_dentry_release(&p, req->r_dentry,
1711                       mds, req->r_dentry_drop, req->r_dentry_unless);
1712        if (req->r_old_dentry_drop)
1713                releases += ceph_encode_dentry_release(&p, req->r_old_dentry,
1714                       mds, req->r_old_dentry_drop, req->r_old_dentry_unless);
1715        if (req->r_old_inode_drop)
1716                releases += ceph_encode_inode_release(&p,
1717                      req->r_old_dentry->d_inode,
1718                      mds, req->r_old_inode_drop, req->r_old_inode_unless, 0);
1719        head->num_releases = cpu_to_le16(releases);
1720
1721        BUG_ON(p > end);
1722        msg->front.iov_len = p - msg->front.iov_base;
1723        msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
1724
1725        if (req->r_data_len) {
1726                /* outbound data set only by ceph_sync_setxattr() */
1727                BUG_ON(!req->r_pages);
1728                ceph_msg_data_add_pages(msg, req->r_pages, req->r_data_len, 0);
1729        }
1730
1731        msg->hdr.data_len = cpu_to_le32(req->r_data_len);
1732        msg->hdr.data_off = cpu_to_le16(0);
1733
1734out_free2:
1735        if (freepath2)
1736                kfree((char *)path2);
1737out_free1:
1738        if (freepath1)
1739                kfree((char *)path1);
1740out:
1741        return msg;
1742}
1743
1744/*
1745 * called under mdsc->mutex if error, under no mutex if
1746 * success.
1747 */
1748static void complete_request(struct ceph_mds_client *mdsc,
1749                             struct ceph_mds_request *req)
1750{
1751        if (req->r_callback)
1752                req->r_callback(mdsc, req);
1753        else
1754                complete_all(&req->r_completion);
1755}
1756
1757/*
1758 * called under mdsc->mutex
1759 */
1760static int __prepare_send_request(struct ceph_mds_client *mdsc,
1761                                  struct ceph_mds_request *req,
1762                                  int mds)
1763{
1764        struct ceph_mds_request_head *rhead;
1765        struct ceph_msg *msg;
1766        int flags = 0;
1767
1768        req->r_attempts++;
1769        if (req->r_inode) {
1770                struct ceph_cap *cap =
1771                        ceph_get_cap_for_mds(ceph_inode(req->r_inode), mds);
1772
1773                if (cap)
1774                        req->r_sent_on_mseq = cap->mseq;
1775                else
1776                        req->r_sent_on_mseq = -1;
1777        }
1778        dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req,
1779             req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts);
1780
1781        if (req->r_got_unsafe) {
1782                /*
1783                 * Replay.  Do not regenerate message (and rebuild
1784                 * paths, etc.); just use the original message.
1785                 * Rebuilding paths will break for renames because
1786                 * d_move mangles the src name.
1787                 */
1788                msg = req->r_request;
1789                rhead = msg->front.iov_base;
1790
1791                flags = le32_to_cpu(rhead->flags);
1792                flags |= CEPH_MDS_FLAG_REPLAY;
1793                rhead->flags = cpu_to_le32(flags);
1794
1795                if (req->r_target_inode)
1796                        rhead->ino = cpu_to_le64(ceph_ino(req->r_target_inode));
1797
1798                rhead->num_retry = req->r_attempts - 1;
1799
1800                /* remove cap/dentry releases from message */
1801                rhead->num_releases = 0;
1802                msg->hdr.front_len = cpu_to_le32(req->r_request_release_offset);
1803                msg->front.iov_len = req->r_request_release_offset;
1804                return 0;
1805        }
1806
1807        if (req->r_request) {
1808                ceph_msg_put(req->r_request);
1809                req->r_request = NULL;
1810        }
1811        msg = create_request_message(mdsc, req, mds);
1812        if (IS_ERR(msg)) {
1813                req->r_err = PTR_ERR(msg);
1814                complete_request(mdsc, req);
1815                return PTR_ERR(msg);
1816        }
1817        req->r_request = msg;
1818
1819        rhead = msg->front.iov_base;
1820        rhead->oldest_client_tid = cpu_to_le64(__get_oldest_tid(mdsc));
1821        if (req->r_got_unsafe)
1822                flags |= CEPH_MDS_FLAG_REPLAY;
1823        if (req->r_locked_dir)
1824                flags |= CEPH_MDS_FLAG_WANT_DENTRY;
1825        rhead->flags = cpu_to_le32(flags);
1826        rhead->num_fwd = req->r_num_fwd;
1827        rhead->num_retry = req->r_attempts - 1;
1828        rhead->ino = 0;
1829
1830        dout(" r_locked_dir = %p\n", req->r_locked_dir);
1831        return 0;
1832}
1833
1834/*
1835 * send request, or put it on the appropriate wait list.
1836 */
1837static int __do_request(struct ceph_mds_client *mdsc,
1838                        struct ceph_mds_request *req)
1839{
1840        struct ceph_mds_session *session = NULL;
1841        int mds = -1;
1842        int err = -EAGAIN;
1843
1844        if (req->r_err || req->r_got_result)
1845                goto out;
1846
1847        if (req->r_timeout &&
1848            time_after_eq(jiffies, req->r_started + req->r_timeout)) {
1849                dout("do_request timed out\n");
1850                err = -EIO;
1851                goto finish;
1852        }
1853
1854        put_request_session(req);
1855
1856        mds = __choose_mds(mdsc, req);
1857        if (mds < 0 ||
1858            ceph_mdsmap_get_state(mdsc->mdsmap, mds) < CEPH_MDS_STATE_ACTIVE) {
1859                dout("do_request no mds or not active, waiting for map\n");
1860                list_add(&req->r_wait, &mdsc->waiting_for_map);
1861                goto out;
1862        }
1863
1864        /* get, open session */
1865        session = __ceph_lookup_mds_session(mdsc, mds);
1866        if (!session) {
1867                session = register_session(mdsc, mds);
1868                if (IS_ERR(session)) {
1869                        err = PTR_ERR(session);
1870                        goto finish;
1871                }
1872        }
1873        req->r_session = get_session(session);
1874
1875        dout("do_request mds%d session %p state %s\n", mds, session,
1876             session_state_name(session->s_state));
1877        if (session->s_state != CEPH_MDS_SESSION_OPEN &&
1878            session->s_state != CEPH_MDS_SESSION_HUNG) {
1879                if (session->s_state == CEPH_MDS_SESSION_NEW ||
1880                    session->s_state == CEPH_MDS_SESSION_CLOSING)
1881                        __open_session(mdsc, session);
1882                list_add(&req->r_wait, &session->s_waiting);
1883                goto out_session;
1884        }
1885
1886        /* send request */
1887        req->r_resend_mds = -1;   /* forget any previous mds hint */
1888
1889        if (req->r_request_started == 0)   /* note request start time */
1890                req->r_request_started = jiffies;
1891
1892        err = __prepare_send_request(mdsc, req, mds);
1893        if (!err) {
1894                ceph_msg_get(req->r_request);
1895                ceph_con_send(&session->s_con, req->r_request);
1896        }
1897
1898out_session:
1899        ceph_put_mds_session(session);
1900out:
1901        return err;
1902
1903finish:
1904        req->r_err = err;
1905        complete_request(mdsc, req);
1906        goto out;
1907}
1908
1909/*
1910 * called under mdsc->mutex
1911 */
1912static void __wake_requests(struct ceph_mds_client *mdsc,
1913                            struct list_head *head)
1914{
1915        struct ceph_mds_request *req;
1916        LIST_HEAD(tmp_list);
1917
1918        list_splice_init(head, &tmp_list);
1919
1920        while (!list_empty(&tmp_list)) {
1921                req = list_entry(tmp_list.next,
1922                                 struct ceph_mds_request, r_wait);
1923                list_del_init(&req->r_wait);
1924                dout(" wake request %p tid %llu\n", req, req->r_tid);
1925                __do_request(mdsc, req);
1926        }
1927}
1928
1929/*
1930 * Wake up threads with requests pending for @mds, so that they can
1931 * resubmit their requests to a possibly different mds.
1932 */
1933static void kick_requests(struct ceph_mds_client *mdsc, int mds)
1934{
1935        struct ceph_mds_request *req;
1936        struct rb_node *p;
1937
1938        dout("kick_requests mds%d\n", mds);
1939        for (p = rb_first(&mdsc->request_tree); p; p = rb_next(p)) {
1940                req = rb_entry(p, struct ceph_mds_request, r_node);
1941                if (req->r_got_unsafe)
1942                        continue;
1943                if (req->r_session &&
1944                    req->r_session->s_mds == mds) {
1945                        dout(" kicking tid %llu\n", req->r_tid);
1946                        __do_request(mdsc, req);
1947                }
1948        }
1949}
1950
1951void ceph_mdsc_submit_request(struct ceph_mds_client *mdsc,
1952                              struct ceph_mds_request *req)
1953{
1954        dout("submit_request on %p\n", req);
1955        mutex_lock(&mdsc->mutex);
1956        __register_request(mdsc, req, NULL);
1957        __do_request(mdsc, req);
1958        mutex_unlock(&mdsc->mutex);
1959}
1960
1961/*
1962 * Synchrously perform an mds request.  Take care of all of the
1963 * session setup, forwarding, retry details.
1964 */
1965int ceph_mdsc_do_request(struct ceph_mds_client *mdsc,
1966                         struct inode *dir,
1967                         struct ceph_mds_request *req)
1968{
1969        int err;
1970
1971        dout("do_request on %p\n", req);
1972
1973        /* take CAP_PIN refs for r_inode, r_locked_dir, r_old_dentry */
1974        if (req->r_inode)
1975                ceph_get_cap_refs(ceph_inode(req->r_inode), CEPH_CAP_PIN);
1976        if (req->r_locked_dir)
1977                ceph_get_cap_refs(ceph_inode(req->r_locked_dir), CEPH_CAP_PIN);
1978        if (req->r_old_dentry)
1979                ceph_get_cap_refs(ceph_inode(req->r_old_dentry_dir),
1980                                  CEPH_CAP_PIN);
1981
1982        /* issue */
1983        mutex_lock(&mdsc->mutex);
1984        __register_request(mdsc, req, dir);
1985        __do_request(mdsc, req);
1986
1987        if (req->r_err) {
1988                err = req->r_err;
1989                __unregister_request(mdsc, req);
1990                dout("do_request early error %d\n", err);
1991                goto out;
1992        }
1993
1994        /* wait */
1995        mutex_unlock(&mdsc->mutex);
1996        dout("do_request waiting\n");
1997        if (req->r_timeout) {
1998                err = (long)wait_for_completion_killable_timeout(
1999                        &req->r_completion, req->r_timeout);
2000                if (err == 0)
2001                        err = -EIO;
2002        } else {
2003                err = wait_for_completion_killable(&req->r_completion);
2004        }
2005        dout("do_request waited, got %d\n", err);
2006        mutex_lock(&mdsc->mutex);
2007
2008        /* only abort if we didn't race with a real reply */
2009        if (req->r_got_result) {
2010                err = le32_to_cpu(req->r_reply_info.head->result);
2011        } else if (err < 0) {
2012                dout("aborted request %lld with %d\n", req->r_tid, err);
2013
2014                /*
2015                 * ensure we aren't running concurrently with
2016                 * ceph_fill_trace or ceph_readdir_prepopulate, which
2017                 * rely on locks (dir mutex) held by our caller.
2018                 */
2019                mutex_lock(&req->r_fill_mutex);
2020                req->r_err = err;
2021                req->r_aborted = true;
2022                mutex_unlock(&req->r_fill_mutex);
2023
2024                if (req->r_locked_dir &&
2025                    (req->r_op & CEPH_MDS_OP_WRITE))
2026                        ceph_invalidate_dir_request(req);
2027        } else {
2028                err = req->r_err;
2029        }
2030
2031out:
2032        mutex_unlock(&mdsc->mutex);
2033        dout("do_request %p done, result %d\n", req, err);
2034        return err;
2035}
2036
2037/*
2038 * Invalidate dir's completeness, dentry lease state on an aborted MDS
2039 * namespace request.
2040 */
2041void ceph_invalidate_dir_request(struct ceph_mds_request *req)
2042{
2043        struct inode *inode = req->r_locked_dir;
2044
2045        dout("invalidate_dir_request %p (complete, lease(s))\n", inode);
2046
2047        ceph_dir_clear_complete(inode);
2048        if (req->r_dentry)
2049                ceph_invalidate_dentry_lease(req->r_dentry);
2050        if (req->r_old_dentry)
2051                ceph_invalidate_dentry_lease(req->r_old_dentry);
2052}
2053
2054/*
2055 * Handle mds reply.
2056 *
2057 * We take the session mutex and parse and process the reply immediately.
2058 * This preserves the logical ordering of replies, capabilities, etc., sent
2059 * by the MDS as they are applied to our local cache.
2060 */
2061static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
2062{
2063        struct ceph_mds_client *mdsc = session->s_mdsc;
2064        struct ceph_mds_request *req;
2065        struct ceph_mds_reply_head *head = msg->front.iov_base;
2066        struct ceph_mds_reply_info_parsed *rinfo;  /* parsed reply info */
2067        u64 tid;
2068        int err, result;
2069        int mds = session->s_mds;
2070
2071        if (msg->front.iov_len < sizeof(*head)) {
2072                pr_err("mdsc_handle_reply got corrupt (short) reply\n");
2073                ceph_msg_dump(msg);
2074                return;
2075        }
2076
2077        /* get request, session */
2078        tid = le64_to_cpu(msg->hdr.tid);
2079        mutex_lock(&mdsc->mutex);
2080        req = __lookup_request(mdsc, tid);
2081        if (!req) {
2082                dout("handle_reply on unknown tid %llu\n", tid);
2083                mutex_unlock(&mdsc->mutex);
2084                return;
2085        }
2086        dout("handle_reply %p\n", req);
2087
2088        /* correct session? */
2089        if (req->r_session != session) {
2090                pr_err("mdsc_handle_reply got %llu on session mds%d"
2091                       " not mds%d\n", tid, session->s_mds,
2092                       req->r_session ? req->r_session->s_mds : -1);
2093                mutex_unlock(&mdsc->mutex);
2094                goto out;
2095        }
2096
2097        /* dup? */
2098        if ((req->r_got_unsafe && !head->safe) ||
2099            (req->r_got_safe && head->safe)) {
2100                pr_warning("got a dup %s reply on %llu from mds%d\n",
2101                           head->safe ? "safe" : "unsafe", tid, mds);
2102                mutex_unlock(&mdsc->mutex);
2103                goto out;
2104        }
2105        if (req->r_got_safe && !head->safe) {
2106                pr_warning("got unsafe after safe on %llu from mds%d\n",
2107                           tid, mds);
2108                mutex_unlock(&mdsc->mutex);
2109                goto out;
2110        }
2111
2112        result = le32_to_cpu(head->result);
2113
2114        /*
2115         * Handle an ESTALE
2116         * if we're not talking to the authority, send to them
2117         * if the authority has changed while we weren't looking,
2118         * send to new authority
2119         * Otherwise we just have to return an ESTALE
2120         */
2121        if (result == -ESTALE) {
2122                dout("got ESTALE on request %llu", req->r_tid);
2123                if (!req->r_inode) {
2124                        /* do nothing; not an authority problem */
2125                } else if (req->r_direct_mode != USE_AUTH_MDS) {
2126                        dout("not using auth, setting for that now");
2127                        req->r_direct_mode = USE_AUTH_MDS;
2128                        __do_request(mdsc, req);
2129                        mutex_unlock(&mdsc->mutex);
2130                        goto out;
2131                } else  {
2132                        struct ceph_inode_info *ci = ceph_inode(req->r_inode);
2133                        struct ceph_cap *cap = NULL;
2134
2135                        if (req->r_session)
2136                                cap = ceph_get_cap_for_mds(ci,
2137                                                   req->r_session->s_mds);
2138
2139                        dout("already using auth");
2140                        if ((!cap || cap != ci->i_auth_cap) ||
2141                            (cap->mseq != req->r_sent_on_mseq)) {
2142                                dout("but cap changed, so resending");
2143                                __do_request(mdsc, req);
2144                                mutex_unlock(&mdsc->mutex);
2145                                goto out;
2146                        }
2147                }
2148                dout("have to return ESTALE on request %llu", req->r_tid);
2149        }
2150
2151
2152        if (head->safe) {
2153                req->r_got_safe = true;
2154                __unregister_request(mdsc, req);
2155                complete_all(&req->r_safe_completion);
2156
2157                if (req->r_got_unsafe) {
2158                        /*
2159                         * We already handled the unsafe response, now do the
2160                         * cleanup.  No need to examine the response; the MDS
2161                         * doesn't include any result info in the safe
2162                         * response.  And even if it did, there is nothing
2163                         * useful we could do with a revised return value.
2164                         */
2165                        dout("got safe reply %llu, mds%d\n", tid, mds);
2166                        list_del_init(&req->r_unsafe_item);
2167
2168                        /* last unsafe request during umount? */
2169                        if (mdsc->stopping && !__get_oldest_req(mdsc))
2170                                complete_all(&mdsc->safe_umount_waiters);
2171                        mutex_unlock(&mdsc->mutex);
2172                        goto out;
2173                }
2174        } else {
2175                req->r_got_unsafe = true;
2176                list_add_tail(&req->r_unsafe_item, &req->r_session->s_unsafe);
2177        }
2178
2179        dout("handle_reply tid %lld result %d\n", tid, result);
2180        rinfo = &req->r_reply_info;
2181        err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
2182        mutex_unlock(&mdsc->mutex);
2183
2184        mutex_lock(&session->s_mutex);
2185        if (err < 0) {
2186                pr_err("mdsc_handle_reply got corrupt reply mds%d(tid:%lld)\n", mds, tid);
2187                ceph_msg_dump(msg);
2188                goto out_err;
2189        }
2190
2191        /* snap trace */
2192        if (rinfo->snapblob_len) {
2193                down_write(&mdsc->snap_rwsem);
2194                ceph_update_snap_trace(mdsc, rinfo->snapblob,
2195                               rinfo->snapblob + rinfo->snapblob_len,
2196                               le32_to_cpu(head->op) == CEPH_MDS_OP_RMSNAP);
2197                downgrade_write(&mdsc->snap_rwsem);
2198        } else {
2199                down_read(&mdsc->snap_rwsem);
2200        }
2201
2202        /* insert trace into our cache */
2203        mutex_lock(&req->r_fill_mutex);
2204        err = ceph_fill_trace(mdsc->fsc->sb, req, req->r_session);
2205        if (err == 0) {
2206                if (result == 0 && (req->r_op == CEPH_MDS_OP_READDIR ||
2207                                    req->r_op == CEPH_MDS_OP_LSSNAP) &&
2208                    rinfo->dir_nr)
2209                        ceph_readdir_prepopulate(req, req->r_session);
2210                ceph_unreserve_caps(mdsc, &req->r_caps_reservation);
2211        }
2212        mutex_unlock(&req->r_fill_mutex);
2213
2214        up_read(&mdsc->snap_rwsem);
2215out_err:
2216        mutex_lock(&mdsc->mutex);
2217        if (!req->r_aborted) {
2218                if (err) {
2219                        req->r_err = err;
2220                } else {
2221                        req->r_reply = msg;
2222                        ceph_msg_get(msg);
2223                        req->r_got_result = true;
2224                }
2225        } else {
2226                dout("reply arrived after request %lld was aborted\n", tid);
2227        }
2228        mutex_unlock(&mdsc->mutex);
2229
2230        ceph_add_cap_releases(mdsc, req->r_session);
2231        mutex_unlock(&session->s_mutex);
2232
2233        /* kick calling process */
2234        complete_request(mdsc, req);
2235out:
2236        ceph_mdsc_put_request(req);
2237        return;
2238}
2239
2240
2241
2242/*
2243 * handle mds notification that our request has been forwarded.
2244 */
2245static void handle_forward(struct ceph_mds_client *mdsc,
2246                           struct ceph_mds_session *session,
2247                           struct ceph_msg *msg)
2248{
2249        struct ceph_mds_request *req;
2250        u64 tid = le64_to_cpu(msg->hdr.tid);
2251        u32 next_mds;
2252        u32 fwd_seq;
2253        int err = -EINVAL;
2254        void *p = msg->front.iov_base;
2255        void *end = p + msg->front.iov_len;
2256
2257        ceph_decode_need(&p, end, 2*sizeof(u32), bad);
2258        next_mds = ceph_decode_32(&p);
2259        fwd_seq = ceph_decode_32(&p);
2260
2261        mutex_lock(&mdsc->mutex);
2262        req = __lookup_request(mdsc, tid);
2263        if (!req) {
2264                dout("forward tid %llu to mds%d - req dne\n", tid, next_mds);
2265                goto out;  /* dup reply? */
2266        }
2267
2268        if (req->r_aborted) {
2269                dout("forward tid %llu aborted, unregistering\n", tid);
2270                __unregister_request(mdsc, req);
2271        } else if (fwd_seq <= req->r_num_fwd) {
2272                dout("forward tid %llu to mds%d - old seq %d <= %d\n",
2273                     tid, next_mds, req->r_num_fwd, fwd_seq);
2274        } else {
2275                /* resend. forward race not possible; mds would drop */
2276                dout("forward tid %llu to mds%d (we resend)\n", tid, next_mds);
2277                BUG_ON(req->r_err);
2278                BUG_ON(req->r_got_result);
2279                req->r_num_fwd = fwd_seq;
2280                req->r_resend_mds = next_mds;
2281                put_request_session(req);
2282                __do_request(mdsc, req);
2283        }
2284        ceph_mdsc_put_request(req);
2285out:
2286        mutex_unlock(&mdsc->mutex);
2287        return;
2288
2289bad:
2290        pr_err("mdsc_handle_forward decode error err=%d\n", err);
2291}
2292
2293/*
2294 * handle a mds session control message
2295 */
2296static void handle_session(struct ceph_mds_session *session,
2297                           struct ceph_msg *msg)
2298{
2299        struct ceph_mds_client *mdsc = session->s_mdsc;
2300        u32 op;
2301        u64 seq;
2302        int mds = session->s_mds;
2303        struct ceph_mds_session_head *h = msg->front.iov_base;
2304        int wake = 0;
2305
2306        /* decode */
2307        if (msg->front.iov_len != sizeof(*h))
2308                goto bad;
2309        op = le32_to_cpu(h->op);
2310        seq = le64_to_cpu(h->seq);
2311
2312        mutex_lock(&mdsc->mutex);
2313        if (op == CEPH_SESSION_CLOSE)
2314                __unregister_session(mdsc, session);
2315        /* FIXME: this ttl calculation is generous */
2316        session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose;
2317        mutex_unlock(&mdsc->mutex);
2318
2319        mutex_lock(&session->s_mutex);
2320
2321        dout("handle_session mds%d %s %p state %s seq %llu\n",
2322             mds, ceph_session_op_name(op), session,
2323             session_state_name(session->s_state), seq);
2324
2325        if (session->s_state == CEPH_MDS_SESSION_HUNG) {
2326                session->s_state = CEPH_MDS_SESSION_OPEN;
2327                pr_info("mds%d came back\n", session->s_mds);
2328        }
2329
2330        switch (op) {
2331        case CEPH_SESSION_OPEN:
2332                if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2333                        pr_info("mds%d reconnect success\n", session->s_mds);
2334                session->s_state = CEPH_MDS_SESSION_OPEN;
2335                renewed_caps(mdsc, session, 0);
2336                wake = 1;
2337                if (mdsc->stopping)
2338                        __close_session(mdsc, session);
2339                break;
2340
2341        case CEPH_SESSION_RENEWCAPS:
2342                if (session->s_renew_seq == seq)
2343                        renewed_caps(mdsc, session, 1);
2344                break;
2345
2346        case CEPH_SESSION_CLOSE:
2347                if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
2348                        pr_info("mds%d reconnect denied\n", session->s_mds);
2349                remove_session_caps(session);
2350                wake = 1; /* for good measure */
2351                wake_up_all(&mdsc->session_close_wq);
2352                kick_requests(mdsc, mds);
2353                break;
2354
2355        case CEPH_SESSION_STALE:
2356                pr_info("mds%d caps went stale, renewing\n",
2357                        session->s_mds);
2358                spin_lock(&session->s_gen_ttl_lock);
2359                session->s_cap_gen++;
2360                session->s_cap_ttl = jiffies - 1;
2361                spin_unlock(&session->s_gen_ttl_lock);
2362                send_renew_caps(mdsc, session);
2363                break;
2364
2365        case CEPH_SESSION_RECALL_STATE:
2366                trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
2367                break;
2368
2369        default:
2370                pr_err("mdsc_handle_session bad op %d mds%d\n", op, mds);
2371                WARN_ON(1);
2372        }
2373
2374        mutex_unlock(&session->s_mutex);
2375        if (wake) {
2376                mutex_lock(&mdsc->mutex);
2377                __wake_requests(mdsc, &session->s_waiting);
2378                mutex_unlock(&mdsc->mutex);
2379        }
2380        return;
2381
2382bad:
2383        pr_err("mdsc_handle_session corrupt message mds%d len %d\n", mds,
2384               (int)msg->front.iov_len);
2385        ceph_msg_dump(msg);
2386        return;
2387}
2388
2389
2390/*
2391 * called under session->mutex.
2392 */
2393static void replay_unsafe_requests(struct ceph_mds_client *mdsc,
2394                                   struct ceph_mds_session *session)
2395{
2396        struct ceph_mds_request *req, *nreq;
2397        int err;
2398
2399        dout("replay_unsafe_requests mds%d\n", session->s_mds);
2400
2401        mutex_lock(&mdsc->mutex);
2402        list_for_each_entry_safe(req, nreq, &session->s_unsafe, r_unsafe_item) {
2403                err = __prepare_send_request(mdsc, req, session->s_mds);
2404                if (!err) {
2405                        ceph_msg_get(req->r_request);
2406                        ceph_con_send(&session->s_con, req->r_request);
2407                }
2408        }
2409        mutex_unlock(&mdsc->mutex);
2410}
2411
2412/*
2413 * Encode information about a cap for a reconnect with the MDS.
2414 */
2415static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
2416                          void *arg)
2417{
2418        union {
2419                struct ceph_mds_cap_reconnect v2;
2420                struct ceph_mds_cap_reconnect_v1 v1;
2421        } rec;
2422        size_t reclen;
2423        struct ceph_inode_info *ci;
2424        struct ceph_reconnect_state *recon_state = arg;
2425        struct ceph_pagelist *pagelist = recon_state->pagelist;
2426        char *path;
2427        int pathlen, err;
2428        u64 pathbase;
2429        struct dentry *dentry;
2430
2431        ci = cap->ci;
2432
2433        dout(" adding %p ino %llx.%llx cap %p %lld %s\n",
2434             inode, ceph_vinop(inode), cap, cap->cap_id,
2435             ceph_cap_string(cap->issued));
2436        err = ceph_pagelist_encode_64(pagelist, ceph_ino(inode));
2437        if (err)
2438                return err;
2439
2440        dentry = d_find_alias(inode);
2441        if (dentry) {
2442                path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase, 0);
2443                if (IS_ERR(path)) {
2444                        err = PTR_ERR(path);
2445                        goto out_dput;
2446                }
2447        } else {
2448                path = NULL;
2449                pathlen = 0;
2450        }
2451        err = ceph_pagelist_encode_string(pagelist, path, pathlen);
2452        if (err)
2453                goto out_free;
2454
2455        spin_lock(&ci->i_ceph_lock);
2456        cap->seq = 0;        /* reset cap seq */
2457        cap->issue_seq = 0;  /* and issue_seq */
2458        cap->mseq = 0;       /* and migrate_seq */
2459
2460        if (recon_state->flock) {
2461                rec.v2.cap_id = cpu_to_le64(cap->cap_id);
2462                rec.v2.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2463                rec.v2.issued = cpu_to_le32(cap->issued);
2464                rec.v2.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2465                rec.v2.pathbase = cpu_to_le64(pathbase);
2466                rec.v2.flock_len = 0;
2467                reclen = sizeof(rec.v2);
2468        } else {
2469                rec.v1.cap_id = cpu_to_le64(cap->cap_id);
2470                rec.v1.wanted = cpu_to_le32(__ceph_caps_wanted(ci));
2471                rec.v1.issued = cpu_to_le32(cap->issued);
2472                rec.v1.size = cpu_to_le64(inode->i_size);
2473                ceph_encode_timespec(&rec.v1.mtime, &inode->i_mtime);
2474                ceph_encode_timespec(&rec.v1.atime, &inode->i_atime);
2475                rec.v1.snaprealm = cpu_to_le64(ci->i_snap_realm->ino);
2476                rec.v1.pathbase = cpu_to_le64(pathbase);
2477                reclen = sizeof(rec.v1);
2478        }
2479        spin_unlock(&ci->i_ceph_lock);
2480
2481        if (recon_state->flock) {
2482                int num_fcntl_locks, num_flock_locks;
2483                struct ceph_filelock *flocks;
2484
2485encode_again:
2486                spin_lock(&inode->i_lock);
2487                ceph_count_locks(inode, &num_fcntl_locks, &num_flock_locks);
2488                spin_unlock(&inode->i_lock);
2489                flocks = kmalloc((num_fcntl_locks+num_flock_locks) *
2490                                 sizeof(struct ceph_filelock), GFP_NOFS);
2491                if (!flocks) {
2492                        err = -ENOMEM;
2493                        goto out_free;
2494                }
2495                spin_lock(&inode->i_lock);
2496                err = ceph_encode_locks_to_buffer(inode, flocks,
2497                                                  num_fcntl_locks,
2498                                                  num_flock_locks);
2499                spin_unlock(&inode->i_lock);
2500                if (err) {
2501                        kfree(flocks);
2502                        if (err == -ENOSPC)
2503                                goto encode_again;
2504                        goto out_free;
2505                }
2506                /*
2507                 * number of encoded locks is stable, so copy to pagelist
2508                 */
2509                rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
2510                                    (num_fcntl_locks+num_flock_locks) *
2511                                    sizeof(struct ceph_filelock));
2512                err = ceph_pagelist_append(pagelist, &rec, reclen);
2513                if (!err)
2514                        err = ceph_locks_to_pagelist(flocks, pagelist,
2515                                                     num_fcntl_locks,
2516                                                     num_flock_locks);
2517                kfree(flocks);
2518        } else {
2519                err = ceph_pagelist_append(pagelist, &rec, reclen);
2520        }
2521out_free:
2522        kfree(path);
2523out_dput:
2524        dput(dentry);
2525        return err;
2526}
2527
2528
2529/*
2530 * If an MDS fails and recovers, clients need to reconnect in order to
2531 * reestablish shared state.  This includes all caps issued through
2532 * this session _and_ the snap_realm hierarchy.  Because it's not
2533 * clear which snap realms the mds cares about, we send everything we
2534 * know about.. that ensures we'll then get any new info the
2535 * recovering MDS might have.
2536 *
2537 * This is a relatively heavyweight operation, but it's rare.
2538 *
2539 * called with mdsc->mutex held.
2540 */
2541static void send_mds_reconnect(struct ceph_mds_client *mdsc,
2542                               struct ceph_mds_session *session)
2543{
2544        struct ceph_msg *reply;
2545        struct rb_node *p;
2546        int mds = session->s_mds;
2547        int err = -ENOMEM;
2548        struct ceph_pagelist *pagelist;
2549        struct ceph_reconnect_state recon_state;
2550
2551        pr_info("mds%d reconnect start\n", mds);
2552
2553        pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
2554        if (!pagelist)
2555                goto fail_nopagelist;
2556        ceph_pagelist_init(pagelist);
2557
2558        reply = ceph_msg_new(CEPH_MSG_CLIENT_RECONNECT, 0, GFP_NOFS, false);
2559        if (!reply)
2560                goto fail_nomsg;
2561
2562        mutex_lock(&session->s_mutex);
2563        session->s_state = CEPH_MDS_SESSION_RECONNECTING;
2564        session->s_seq = 0;
2565
2566        ceph_con_close(&session->s_con);
2567        ceph_con_open(&session->s_con,
2568                      CEPH_ENTITY_TYPE_MDS, mds,
2569                      ceph_mdsmap_get_addr(mdsc->mdsmap, mds));
2570
2571        /* replay unsafe requests */
2572        replay_unsafe_requests(mdsc, session);
2573
2574        down_read(&mdsc->snap_rwsem);
2575
2576        dout("session %p state %s\n", session,
2577             session_state_name(session->s_state));
2578
2579        /* drop old cap expires; we're about to reestablish that state */
2580        discard_cap_releases(mdsc, session);
2581
2582        /* traverse this session's caps */
2583        err = ceph_pagelist_encode_32(pagelist, session->s_nr_caps);
2584        if (err)
2585                goto fail;
2586
2587        recon_state.pagelist = pagelist;
2588        recon_state.flock = session->s_con.peer_features & CEPH_FEATURE_FLOCK;
2589        err = iterate_session_caps(session, encode_caps_cb, &recon_state);
2590        if (err < 0)
2591                goto fail;
2592
2593        /*
2594         * snaprealms.  we provide mds with the ino, seq (version), and
2595         * parent for all of our realms.  If the mds has any newer info,
2596         * it will tell us.
2597         */
2598        for (p = rb_first(&mdsc->snap_realms); p; p = rb_next(p)) {
2599                struct ceph_snap_realm *realm =
2600                        rb_entry(p, struct ceph_snap_realm, node);
2601                struct ceph_mds_snaprealm_reconnect sr_rec;
2602
2603                dout(" adding snap realm %llx seq %lld parent %llx\n",
2604                     realm->ino, realm->seq, realm->parent_ino);
2605                sr_rec.ino = cpu_to_le64(realm->ino);
2606                sr_rec.seq = cpu_to_le64(realm->seq);
2607                sr_rec.parent = cpu_to_le64(realm->parent_ino);
2608                err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
2609                if (err)
2610                        goto fail;
2611        }
2612
2613        if (recon_state.flock)
2614                reply->hdr.version = cpu_to_le16(2);
2615        if (pagelist->length) {
2616                /* set up outbound data if we have any */
2617                reply->hdr.data_len = cpu_to_le32(pagelist->length);
2618                ceph_msg_data_add_pagelist(reply, pagelist);
2619        }
2620        ceph_con_send(&session->s_con, reply);
2621
2622        mutex_unlock(&session->s_mutex);
2623
2624        mutex_lock(&mdsc->mutex);
2625        __wake_requests(mdsc, &session->s_waiting);
2626        mutex_unlock(&mdsc->mutex);
2627
2628        up_read(&mdsc->snap_rwsem);
2629        return;
2630
2631fail:
2632        ceph_msg_put(reply);
2633        up_read(&mdsc->snap_rwsem);
2634        mutex_unlock(&session->s_mutex);
2635fail_nomsg:
2636        ceph_pagelist_release(pagelist);
2637        kfree(pagelist);
2638fail_nopagelist:
2639        pr_err("error %d preparing reconnect for mds%d\n", err, mds);
2640        return;
2641}
2642
2643
2644/*
2645 * compare old and new mdsmaps, kicking requests
2646 * and closing out old connections as necessary
2647 *
2648 * called under mdsc->mutex.
2649 */
2650static void check_new_map(struct ceph_mds_client *mdsc,
2651                          struct ceph_mdsmap *newmap,
2652                          struct ceph_mdsmap *oldmap)
2653{
2654        int i;
2655        int oldstate, newstate;
2656        struct ceph_mds_session *s;
2657
2658        dout("check_new_map new %u old %u\n",
2659             newmap->m_epoch, oldmap->m_epoch);
2660
2661        for (i = 0; i < oldmap->m_max_mds && i < mdsc->max_sessions; i++) {
2662                if (mdsc->sessions[i] == NULL)
2663                        continue;
2664                s = mdsc->sessions[i];
2665                oldstate = ceph_mdsmap_get_state(oldmap, i);
2666                newstate = ceph_mdsmap_get_state(newmap, i);
2667
2668                dout("check_new_map mds%d state %s%s -> %s%s (session %s)\n",
2669                     i, ceph_mds_state_name(oldstate),
2670                     ceph_mdsmap_is_laggy(oldmap, i) ? " (laggy)" : "",
2671                     ceph_mds_state_name(newstate),
2672                     ceph_mdsmap_is_laggy(newmap, i) ? " (laggy)" : "",
2673                     session_state_name(s->s_state));
2674
2675                if (i >= newmap->m_max_mds ||
2676                    memcmp(ceph_mdsmap_get_addr(oldmap, i),
2677                           ceph_mdsmap_get_addr(newmap, i),
2678                           sizeof(struct ceph_entity_addr))) {
2679                        if (s->s_state == CEPH_MDS_SESSION_OPENING) {
2680                                /* the session never opened, just close it
2681                                 * out now */
2682                                __wake_requests(mdsc, &s->s_waiting);
2683                                __unregister_session(mdsc, s);
2684                        } else {
2685                                /* just close it */
2686                                mutex_unlock(&mdsc->mutex);
2687                                mutex_lock(&s->s_mutex);
2688                                mutex_lock(&mdsc->mutex);
2689                                ceph_con_close(&s->s_con);
2690                                mutex_unlock(&s->s_mutex);
2691                                s->s_state = CEPH_MDS_SESSION_RESTARTING;
2692                        }
2693
2694                        /* kick any requests waiting on the recovering mds */
2695                        kick_requests(mdsc, i);
2696                } else if (oldstate == newstate) {
2697                        continue;  /* nothing new with this mds */
2698                }
2699
2700                /*
2701                 * send reconnect?
2702                 */
2703                if (s->s_state == CEPH_MDS_SESSION_RESTARTING &&
2704                    newstate >= CEPH_MDS_STATE_RECONNECT) {
2705                        mutex_unlock(&mdsc->mutex);
2706                        send_mds_reconnect(mdsc, s);
2707                        mutex_lock(&mdsc->mutex);
2708                }
2709
2710                /*
2711                 * kick request on any mds that has gone active.
2712                 */
2713                if (oldstate < CEPH_MDS_STATE_ACTIVE &&
2714                    newstate >= CEPH_MDS_STATE_ACTIVE) {
2715                        if (oldstate != CEPH_MDS_STATE_CREATING &&
2716                            oldstate != CEPH_MDS_STATE_STARTING)
2717                                pr_info("mds%d recovery completed\n", s->s_mds);
2718                        kick_requests(mdsc, i);
2719                        ceph_kick_flushing_caps(mdsc, s);
2720                        wake_up_session_caps(s, 1);
2721                }
2722        }
2723
2724        for (i = 0; i < newmap->m_max_mds && i < mdsc->max_sessions; i++) {
2725                s = mdsc->sessions[i];
2726                if (!s)
2727                        continue;
2728                if (!ceph_mdsmap_is_laggy(newmap, i))
2729                        continue;
2730                if (s->s_state == CEPH_MDS_SESSION_OPEN ||
2731                    s->s_state == CEPH_MDS_SESSION_HUNG ||
2732                    s->s_state == CEPH_MDS_SESSION_CLOSING) {
2733                        dout(" connecting to export targets of laggy mds%d\n",
2734                             i);
2735                        __open_export_target_sessions(mdsc, s);
2736                }
2737        }
2738}
2739
2740
2741
2742/*
2743 * leases
2744 */
2745
2746/*
2747 * caller must hold session s_mutex, dentry->d_lock
2748 */
2749void __ceph_mdsc_drop_dentry_lease(struct dentry *dentry)
2750{
2751        struct ceph_dentry_info *di = ceph_dentry(dentry);
2752
2753        ceph_put_mds_session(di->lease_session);
2754        di->lease_session = NULL;
2755}
2756
2757static void handle_lease(struct ceph_mds_client *mdsc,
2758                         struct ceph_mds_session *session,
2759                         struct ceph_msg *msg)
2760{
2761        struct super_block *sb = mdsc->fsc->sb;
2762        struct inode *inode;
2763        struct dentry *parent, *dentry;
2764        struct ceph_dentry_info *di;
2765        int mds = session->s_mds;
2766        struct ceph_mds_lease *h = msg->front.iov_base;
2767        u32 seq;
2768        struct ceph_vino vino;
2769        struct qstr dname;
2770        int release = 0;
2771
2772        dout("handle_lease from mds%d\n", mds);
2773
2774        /* decode */
2775        if (msg->front.iov_len < sizeof(*h) + sizeof(u32))
2776                goto bad;
2777        vino.ino = le64_to_cpu(h->ino);
2778        vino.snap = CEPH_NOSNAP;
2779        seq = le32_to_cpu(h->seq);
2780        dname.name = (void *)h + sizeof(*h) + sizeof(u32);
2781        dname.len = msg->front.iov_len - sizeof(*h) - sizeof(u32);
2782        if (dname.len != get_unaligned_le32(h+1))
2783                goto bad;
2784
2785        mutex_lock(&session->s_mutex);
2786        session->s_seq++;
2787
2788        /* lookup inode */
2789        inode = ceph_find_inode(sb, vino);
2790        dout("handle_lease %s, ino %llx %p %.*s\n",
2791             ceph_lease_op_name(h->action), vino.ino, inode,
2792             dname.len, dname.name);
2793        if (inode == NULL) {
2794                dout("handle_lease no inode %llx\n", vino.ino);
2795                goto release;
2796        }
2797
2798        /* dentry */
2799        parent = d_find_alias(inode);
2800        if (!parent) {
2801                dout("no parent dentry on inode %p\n", inode);
2802                WARN_ON(1);
2803                goto release;  /* hrm... */
2804        }
2805        dname.hash = full_name_hash(dname.name, dname.len);
2806        dentry = d_lookup(parent, &dname);
2807        dput(parent);
2808        if (!dentry)
2809                goto release;
2810
2811        spin_lock(&dentry->d_lock);
2812        di = ceph_dentry(dentry);
2813        switch (h->action) {
2814        case CEPH_MDS_LEASE_REVOKE:
2815                if (di->lease_session == session) {
2816                        if (ceph_seq_cmp(di->lease_seq, seq) > 0)
2817                                h->seq = cpu_to_le32(di->lease_seq);
2818                        __ceph_mdsc_drop_dentry_lease(dentry);
2819                }
2820                release = 1;
2821                break;
2822
2823        case CEPH_MDS_LEASE_RENEW:
2824                if (di->lease_session == session &&
2825                    di->lease_gen == session->s_cap_gen &&
2826                    di->lease_renew_from &&
2827                    di->lease_renew_after == 0) {
2828                        unsigned long duration =
2829                                le32_to_cpu(h->duration_ms) * HZ / 1000;
2830
2831                        di->lease_seq = seq;
2832                        dentry->d_time = di->lease_renew_from + duration;
2833                        di->lease_renew_after = di->lease_renew_from +
2834                                (duration >> 1);
2835                        di->lease_renew_from = 0;
2836                }
2837                break;
2838        }
2839        spin_unlock(&dentry->d_lock);
2840        dput(dentry);
2841
2842        if (!release)
2843                goto out;
2844
2845release:
2846        /* let's just reuse the same message */
2847        h->action = CEPH_MDS_LEASE_REVOKE_ACK;
2848        ceph_msg_get(msg);
2849        ceph_con_send(&session->s_con, msg);
2850
2851out:
2852        iput(inode);
2853        mutex_unlock(&session->s_mutex);
2854        return;
2855
2856bad:
2857        pr_err("corrupt lease message\n");
2858        ceph_msg_dump(msg);
2859}
2860
2861void ceph_mdsc_lease_send_msg(struct ceph_mds_session *session,
2862                              struct inode *inode,
2863                              struct dentry *dentry, char action,
2864                              u32 seq)
2865{
2866        struct ceph_msg *msg;
2867        struct ceph_mds_lease *lease;
2868        int len = sizeof(*lease) + sizeof(u32);
2869        int dnamelen = 0;
2870
2871        dout("lease_send_msg inode %p dentry %p %s to mds%d\n",
2872             inode, dentry, ceph_lease_op_name(action), session->s_mds);
2873        dnamelen = dentry->d_name.len;
2874        len += dnamelen;
2875
2876        msg = ceph_msg_new(CEPH_MSG_CLIENT_LEASE, len, GFP_NOFS, false);
2877        if (!msg)
2878                return;
2879        lease = msg->front.iov_base;
2880        lease->action = action;
2881        lease->ino = cpu_to_le64(ceph_vino(inode).ino);
2882        lease->first = lease->last = cpu_to_le64(ceph_vino(inode).snap);
2883        lease->seq = cpu_to_le32(seq);
2884        put_unaligned_le32(dnamelen, lease + 1);
2885        memcpy((void *)(lease + 1) + 4, dentry->d_name.name, dnamelen);
2886
2887        /*
2888         * if this is a preemptive lease RELEASE, no need to
2889         * flush request stream, since the actual request will
2890         * soon follow.
2891         */
2892        msg->more_to_follow = (action == CEPH_MDS_LEASE_RELEASE);
2893
2894        ceph_con_send(&session->s_con, msg);
2895}
2896
2897/*
2898 * Preemptively release a lease we expect to invalidate anyway.
2899 * Pass @inode always, @dentry is optional.
2900 */
2901void ceph_mdsc_lease_release(struct ceph_mds_client *mdsc, struct inode *inode,
2902                             struct dentry *dentry)
2903{
2904        struct ceph_dentry_info *di;
2905        struct ceph_mds_session *session;
2906        u32 seq;
2907
2908        BUG_ON(inode == NULL);
2909        BUG_ON(dentry == NULL);
2910
2911        /* is dentry lease valid? */
2912        spin_lock(&dentry->d_lock);
2913        di = ceph_dentry(dentry);
2914        if (!di || !di->lease_session ||
2915            di->lease_session->s_mds < 0 ||
2916            di->lease_gen != di->lease_session->s_cap_gen ||
2917            !time_before(jiffies, dentry->d_time)) {
2918                dout("lease_release inode %p dentry %p -- "
2919                     "no lease\n",
2920                     inode, dentry);
2921                spin_unlock(&dentry->d_lock);
2922                return;
2923        }
2924
2925        /* we do have a lease on this dentry; note mds and seq */
2926        session = ceph_get_mds_session(di->lease_session);
2927        seq = di->lease_seq;
2928        __ceph_mdsc_drop_dentry_lease(dentry);
2929        spin_unlock(&dentry->d_lock);
2930
2931        dout("lease_release inode %p dentry %p to mds%d\n",
2932             inode, dentry, session->s_mds);
2933        ceph_mdsc_lease_send_msg(session, inode, dentry,
2934                                 CEPH_MDS_LEASE_RELEASE, seq);
2935        ceph_put_mds_session(session);
2936}
2937
2938/*
2939 * drop all leases (and dentry refs) in preparation for umount
2940 */
2941static void drop_leases(struct ceph_mds_client *mdsc)
2942{
2943        int i;
2944
2945        dout("drop_leases\n");
2946        mutex_lock(&mdsc->mutex);
2947        for (i = 0; i < mdsc->max_sessions; i++) {
2948                struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
2949                if (!s)
2950                        continue;
2951                mutex_unlock(&mdsc->mutex);
2952                mutex_lock(&s->s_mutex);
2953                mutex_unlock(&s->s_mutex);
2954                ceph_put_mds_session(s);
2955                mutex_lock(&mdsc->mutex);
2956        }
2957        mutex_unlock(&mdsc->mutex);
2958}
2959
2960
2961
2962/*
2963 * delayed work -- periodically trim expired leases, renew caps with mds
2964 */
2965static void schedule_delayed(struct ceph_mds_client *mdsc)
2966{
2967        int delay = 5;
2968        unsigned hz = round_jiffies_relative(HZ * delay);
2969        schedule_delayed_work(&mdsc->delayed_work, hz);
2970}
2971
2972static void delayed_work(struct work_struct *work)
2973{
2974        int i;
2975        struct ceph_mds_client *mdsc =
2976                container_of(work, struct ceph_mds_client, delayed_work.work);
2977        int renew_interval;
2978        int renew_caps;
2979
2980        dout("mdsc delayed_work\n");
2981        ceph_check_delayed_caps(mdsc);
2982
2983        mutex_lock(&mdsc->mutex);
2984        renew_interval = mdsc->mdsmap->m_session_timeout >> 2;
2985        renew_caps = time_after_eq(jiffies, HZ*renew_interval +
2986                                   mdsc->last_renew_caps);
2987        if (renew_caps)
2988                mdsc->last_renew_caps = jiffies;
2989
2990        for (i = 0; i < mdsc->max_sessions; i++) {
2991                struct ceph_mds_session *s = __ceph_lookup_mds_session(mdsc, i);
2992                if (s == NULL)
2993                        continue;
2994                if (s->s_state == CEPH_MDS_SESSION_CLOSING) {
2995                        dout("resending session close request for mds%d\n",
2996                             s->s_mds);
2997                        request_close_session(mdsc, s);
2998                        ceph_put_mds_session(s);
2999                        continue;
3000                }
3001                if (s->s_ttl && time_after(jiffies, s->s_ttl)) {
3002                        if (s->s_state == CEPH_MDS_SESSION_OPEN) {
3003                                s->s_state = CEPH_MDS_SESSION_HUNG;
3004                                pr_info("mds%d hung\n", s->s_mds);
3005                        }
3006                }
3007                if (s->s_state < CEPH_MDS_SESSION_OPEN) {
3008                        /* this mds is failed or recovering, just wait */
3009                        ceph_put_mds_session(s);
3010                        continue;
3011                }
3012                mutex_unlock(&mdsc->mutex);
3013
3014                mutex_lock(&s->s_mutex);
3015                if (renew_caps)
3016                        send_renew_caps(mdsc, s);
3017                else
3018                        ceph_con_keepalive(&s->s_con);
3019                ceph_add_cap_releases(mdsc, s);
3020                if (s->s_state == CEPH_MDS_SESSION_OPEN ||
3021                    s->s_state == CEPH_MDS_SESSION_HUNG)
3022                        ceph_send_cap_releases(mdsc, s);
3023                mutex_unlock(&s->s_mutex);
3024                ceph_put_mds_session(s);
3025
3026                mutex_lock(&mdsc->mutex);
3027        }
3028        mutex_unlock(&mdsc->mutex);
3029
3030        schedule_delayed(mdsc);
3031}
3032
3033int ceph_mdsc_init(struct ceph_fs_client *fsc)
3034
3035{
3036        struct ceph_mds_client *mdsc;
3037
3038        mdsc = kzalloc(sizeof(struct ceph_mds_client), GFP_NOFS);
3039        if (!mdsc)
3040                return -ENOMEM;
3041        mdsc->fsc = fsc;
3042        fsc->mdsc = mdsc;
3043        mutex_init(&mdsc->mutex);
3044        mdsc->mdsmap = kzalloc(sizeof(*mdsc->mdsmap), GFP_NOFS);
3045        if (mdsc->mdsmap == NULL) {
3046                kfree(mdsc);
3047                return -ENOMEM;
3048        }
3049
3050        init_completion(&mdsc->safe_umount_waiters);
3051        init_waitqueue_head(&mdsc->session_close_wq);
3052        INIT_LIST_HEAD(&mdsc->waiting_for_map);
3053        mdsc->sessions = NULL;
3054        mdsc->max_sessions = 0;
3055        mdsc->stopping = 0;
3056        init_rwsem(&mdsc->snap_rwsem);
3057        mdsc->snap_realms = RB_ROOT;
3058        INIT_LIST_HEAD(&mdsc->snap_empty);
3059        spin_lock_init(&mdsc->snap_empty_lock);
3060        mdsc->last_tid = 0;
3061        mdsc->request_tree = RB_ROOT;
3062        INIT_DELAYED_WORK(&mdsc->delayed_work, delayed_work);
3063        mdsc->last_renew_caps = jiffies;
3064        INIT_LIST_HEAD(&mdsc->cap_delay_list);
3065        spin_lock_init(&mdsc->cap_delay_lock);
3066        INIT_LIST_HEAD(&mdsc->snap_flush_list);
3067        spin_lock_init(&mdsc->snap_flush_lock);
3068        mdsc->cap_flush_seq = 0;
3069        INIT_LIST_HEAD(&mdsc->cap_dirty);
3070        INIT_LIST_HEAD(&mdsc->cap_dirty_migrating);
3071        mdsc->num_cap_flushing = 0;
3072        spin_lock_init(&mdsc->cap_dirty_lock);
3073        init_waitqueue_head(&mdsc->cap_flushing_wq);
3074        spin_lock_init(&mdsc->dentry_lru_lock);
3075        INIT_LIST_HEAD(&mdsc->dentry_lru);
3076
3077        ceph_caps_init(mdsc);
3078        ceph_adjust_min_caps(mdsc, fsc->min_caps);
3079
3080        return 0;
3081}
3082
3083/*
3084 * Wait for safe replies on open mds requests.  If we time out, drop
3085 * all requests from the tree to avoid dangling dentry refs.
3086 */
3087static void wait_requests(struct ceph_mds_client *mdsc)
3088{
3089        struct ceph_mds_request *req;
3090        struct ceph_fs_client *fsc = mdsc->fsc;
3091
3092        mutex_lock(&mdsc->mutex);
3093        if (__get_oldest_req(mdsc)) {
3094                mutex_unlock(&mdsc->mutex);
3095
3096                dout("wait_requests waiting for requests\n");
3097                wait_for_completion_timeout(&mdsc->safe_umount_waiters,
3098                                    fsc->client->options->mount_timeout * HZ);
3099
3100                /* tear down remaining requests */
3101                mutex_lock(&mdsc->mutex);
3102                while ((req = __get_oldest_req(mdsc))) {
3103                        dout("wait_requests timed out on tid %llu\n",
3104                             req->r_tid);
3105                        __unregister_request(mdsc, req);
3106                }
3107        }
3108        mutex_unlock(&mdsc->mutex);
3109        dout("wait_requests done\n");
3110}
3111
3112/*
3113 * called before mount is ro, and before dentries are torn down.
3114 * (hmm, does this still race with new lookups?)
3115 */
3116void ceph_mdsc_pre_umount(struct ceph_mds_client *mdsc)
3117{
3118        dout("pre_umount\n");
3119        mdsc->stopping = 1;
3120
3121        drop_leases(mdsc);
3122        ceph_flush_dirty_caps(mdsc);
3123        wait_requests(mdsc);
3124
3125        /*
3126         * wait for reply handlers to drop their request refs and
3127         * their inode/dcache refs
3128         */
3129        ceph_msgr_flush();
3130}
3131
3132/*
3133 * wait for all write mds requests to flush.
3134 */
3135static void wait_unsafe_requests(struct ceph_mds_client *mdsc, u64 want_tid)
3136{
3137        struct ceph_mds_request *req = NULL, *nextreq;
3138        struct rb_node *n;
3139
3140        mutex_lock(&mdsc->mutex);
3141        dout("wait_unsafe_requests want %lld\n", want_tid);
3142restart:
3143        req = __get_oldest_req(mdsc);
3144        while (req && req->r_tid <= want_tid) {
3145                /* find next request */
3146                n = rb_next(&req->r_node);
3147                if (n)
3148                        nextreq = rb_entry(n, struct ceph_mds_request, r_node);
3149                else
3150                        nextreq = NULL;
3151                if ((req->r_op & CEPH_MDS_OP_WRITE)) {
3152                        /* write op */
3153                        ceph_mdsc_get_request(req);
3154                        if (nextreq)
3155                                ceph_mdsc_get_request(nextreq);
3156                        mutex_unlock(&mdsc->mutex);
3157                        dout("wait_unsafe_requests  wait on %llu (want %llu)\n",
3158                             req->r_tid, want_tid);
3159                        wait_for_completion(&req->r_safe_completion);
3160                        mutex_lock(&mdsc->mutex);
3161                        ceph_mdsc_put_request(req);
3162                        if (!nextreq)
3163                                break;  /* next dne before, so we're done! */
3164                        if (RB_EMPTY_NODE(&nextreq->r_node)) {
3165                                /* next request was removed from tree */
3166                                ceph_mdsc_put_request(nextreq);
3167                                goto restart;
3168                        }
3169                        ceph_mdsc_put_request(nextreq);  /* won't go away */
3170                }
3171                req = nextreq;
3172        }
3173        mutex_unlock(&mdsc->mutex);
3174        dout("wait_unsafe_requests done\n");
3175}
3176
3177void ceph_mdsc_sync(struct ceph_mds_client *mdsc)
3178{
3179        u64 want_tid, want_flush;
3180
3181        if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3182                return;
3183
3184        dout("sync\n");
3185        mutex_lock(&mdsc->mutex);
3186        want_tid = mdsc->last_tid;
3187        want_flush = mdsc->cap_flush_seq;
3188        mutex_unlock(&mdsc->mutex);
3189        dout("sync want tid %lld flush_seq %lld\n", want_tid, want_flush);
3190
3191        ceph_flush_dirty_caps(mdsc);
3192
3193        wait_unsafe_requests(mdsc, want_tid);
3194        wait_event(mdsc->cap_flushing_wq, check_cap_flush(mdsc, want_flush));
3195}
3196
3197/*
3198 * true if all sessions are closed, or we force unmount
3199 */
3200static bool done_closing_sessions(struct ceph_mds_client *mdsc)
3201{
3202        int i, n = 0;
3203
3204        if (mdsc->fsc->mount_state == CEPH_MOUNT_SHUTDOWN)
3205                return true;
3206
3207        mutex_lock(&mdsc->mutex);
3208        for (i = 0; i < mdsc->max_sessions; i++)
3209                if (mdsc->sessions[i])
3210                        n++;
3211        mutex_unlock(&mdsc->mutex);
3212        return n == 0;
3213}
3214
3215/*
3216 * called after sb is ro.
3217 */
3218void ceph_mdsc_close_sessions(struct ceph_mds_client *mdsc)
3219{
3220        struct ceph_mds_session *session;
3221        int i;
3222        struct ceph_fs_client *fsc = mdsc->fsc;
3223        unsigned long timeout = fsc->client->options->mount_timeout * HZ;
3224
3225        dout("close_sessions\n");
3226
3227        /* close sessions */
3228        mutex_lock(&mdsc->mutex);
3229        for (i = 0; i < mdsc->max_sessions; i++) {
3230                session = __ceph_lookup_mds_session(mdsc, i);
3231                if (!session)
3232                        continue;
3233                mutex_unlock(&mdsc->mutex);
3234                mutex_lock(&session->s_mutex);
3235                __close_session(mdsc, session);
3236                mutex_unlock(&session->s_mutex);
3237                ceph_put_mds_session(session);
3238                mutex_lock(&mdsc->mutex);
3239        }
3240        mutex_unlock(&mdsc->mutex);
3241
3242        dout("waiting for sessions to close\n");
3243        wait_event_timeout(mdsc->session_close_wq, done_closing_sessions(mdsc),
3244                           timeout);
3245
3246        /* tear down remaining sessions */
3247        mutex_lock(&mdsc->mutex);
3248        for (i = 0; i < mdsc->max_sessions; i++) {
3249                if (mdsc->sessions[i]) {
3250                        session = get_session(mdsc->sessions[i]);
3251                        __unregister_session(mdsc, session);
3252                        mutex_unlock(&mdsc->mutex);
3253                        mutex_lock(&session->s_mutex);
3254                        remove_session_caps(session);
3255                        mutex_unlock(&session->s_mutex);
3256                        ceph_put_mds_session(session);
3257                        mutex_lock(&mdsc->mutex);
3258                }
3259        }
3260        WARN_ON(!list_empty(&mdsc->cap_delay_list));
3261        mutex_unlock(&mdsc->mutex);
3262
3263        ceph_cleanup_empty_realms(mdsc);
3264
3265        cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3266
3267        dout("stopped\n");
3268}
3269
3270static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
3271{
3272        dout("stop\n");
3273        cancel_delayed_work_sync(&mdsc->delayed_work); /* cancel timer */
3274        if (mdsc->mdsmap)
3275                ceph_mdsmap_destroy(mdsc->mdsmap);
3276        kfree(mdsc->sessions);
3277        ceph_caps_finalize(mdsc);
3278}
3279
3280void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
3281{
3282        struct ceph_mds_client *mdsc = fsc->mdsc;
3283
3284        dout("mdsc_destroy %p\n", mdsc);
3285        ceph_mdsc_stop(mdsc);
3286
3287        /* flush out any connection work with references to us */
3288        ceph_msgr_flush();
3289
3290        fsc->mdsc = NULL;
3291        kfree(mdsc);
3292        dout("mdsc_destroy %p done\n", mdsc);
3293}
3294
3295
3296/*
3297 * handle mds map update.
3298 */
3299void ceph_mdsc_handle_map(struct ceph_mds_client *mdsc, struct ceph_msg *msg)
3300{
3301        u32 epoch;
3302        u32 maplen;
3303        void *p = msg->front.iov_base;
3304        void *end = p + msg->front.iov_len;
3305        struct ceph_mdsmap *newmap, *oldmap;
3306        struct ceph_fsid fsid;
3307        int err = -EINVAL;
3308
3309        ceph_decode_need(&p, end, sizeof(fsid)+2*sizeof(u32), bad);
3310        ceph_decode_copy(&p, &fsid, sizeof(fsid));
3311        if (ceph_check_fsid(mdsc->fsc->client, &fsid) < 0)
3312                return;
3313        epoch = ceph_decode_32(&p);
3314        maplen = ceph_decode_32(&p);
3315        dout("handle_map epoch %u len %d\n", epoch, (int)maplen);
3316
3317        /* do we need it? */
3318        ceph_monc_got_mdsmap(&mdsc->fsc->client->monc, epoch);
3319        mutex_lock(&mdsc->mutex);
3320        if (mdsc->mdsmap && epoch <= mdsc->mdsmap->m_epoch) {
3321                dout("handle_map epoch %u <= our %u\n",
3322                     epoch, mdsc->mdsmap->m_epoch);
3323                mutex_unlock(&mdsc->mutex);
3324                return;
3325        }
3326
3327        newmap = ceph_mdsmap_decode(&p, end);
3328        if (IS_ERR(newmap)) {
3329                err = PTR_ERR(newmap);
3330                goto bad_unlock;
3331        }
3332
3333        /* swap into place */
3334        if (mdsc->mdsmap) {
3335                oldmap = mdsc->mdsmap;
3336                mdsc->mdsmap = newmap;
3337                check_new_map(mdsc, newmap, oldmap);
3338                ceph_mdsmap_destroy(oldmap);
3339        } else {
3340                mdsc->mdsmap = newmap;  /* first mds map */
3341        }
3342        mdsc->fsc->sb->s_maxbytes = mdsc->mdsmap->m_max_file_size;
3343
3344        __wake_requests(mdsc, &mdsc->waiting_for_map);
3345
3346        mutex_unlock(&mdsc->mutex);
3347        schedule_delayed(mdsc);
3348        return;
3349
3350bad_unlock:
3351        mutex_unlock(&mdsc->mutex);
3352bad:
3353        pr_err("error decoding mdsmap %d\n", err);
3354        return;
3355}
3356
3357static struct ceph_connection *con_get(struct ceph_connection *con)
3358{
3359        struct ceph_mds_session *s = con->private;
3360
3361        if (get_session(s)) {
3362                dout("mdsc con_get %p ok (%d)\n", s, atomic_read(&s->s_ref));
3363                return con;
3364        }
3365        dout("mdsc con_get %p FAIL\n", s);
3366        return NULL;
3367}
3368
3369static void con_put(struct ceph_connection *con)
3370{
3371        struct ceph_mds_session *s = con->private;
3372
3373        dout("mdsc con_put %p (%d)\n", s, atomic_read(&s->s_ref) - 1);
3374        ceph_put_mds_session(s);
3375}
3376
3377/*
3378 * if the client is unresponsive for long enough, the mds will kill
3379 * the session entirely.
3380 */
3381static void peer_reset(struct ceph_connection *con)
3382{
3383        struct ceph_mds_session *s = con->private;
3384        struct ceph_mds_client *mdsc = s->s_mdsc;
3385
3386        pr_warning("mds%d closed our session\n", s->s_mds);
3387        send_mds_reconnect(mdsc, s);
3388}
3389
3390static void dispatch(struct ceph_connection *con, struct ceph_msg *msg)
3391{
3392        struct ceph_mds_session *s = con->private;
3393        struct ceph_mds_client *mdsc = s->s_mdsc;
3394        int type = le16_to_cpu(msg->hdr.type);
3395
3396        mutex_lock(&mdsc->mutex);
3397        if (__verify_registered_session(mdsc, s) < 0) {
3398                mutex_unlock(&mdsc->mutex);
3399                goto out;
3400        }
3401        mutex_unlock(&mdsc->mutex);
3402
3403        switch (type) {
3404        case CEPH_MSG_MDS_MAP:
3405                ceph_mdsc_handle_map(mdsc, msg);
3406                break;
3407        case CEPH_MSG_CLIENT_SESSION:
3408                handle_session(s, msg);
3409                break;
3410        case CEPH_MSG_CLIENT_REPLY:
3411                handle_reply(s, msg);
3412                break;
3413        case CEPH_MSG_CLIENT_REQUEST_FORWARD:
3414                handle_forward(mdsc, s, msg);
3415                break;
3416        case CEPH_MSG_CLIENT_CAPS:
3417                ceph_handle_caps(s, msg);
3418                break;
3419        case CEPH_MSG_CLIENT_SNAP:
3420                ceph_handle_snap(mdsc, s, msg);
3421                break;
3422        case CEPH_MSG_CLIENT_LEASE:
3423                handle_lease(mdsc, s, msg);
3424                break;
3425
3426        default:
3427                pr_err("received unknown message type %d %s\n", type,
3428                       ceph_msg_type_name(type));
3429        }
3430out:
3431        ceph_msg_put(msg);
3432}
3433
3434/*
3435 * authentication
3436 */
3437
3438/*
3439 * Note: returned pointer is the address of a structure that's
3440 * managed separately.  Caller must *not* attempt to free it.
3441 */
3442static struct ceph_auth_handshake *get_authorizer(struct ceph_connection *con,
3443                                        int *proto, int force_new)
3444{
3445        struct ceph_mds_session *s = con->private;
3446        struct ceph_mds_client *mdsc = s->s_mdsc;
3447        struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3448        struct ceph_auth_handshake *auth = &s->s_auth;
3449
3450        if (force_new && auth->authorizer) {
3451                ceph_auth_destroy_authorizer(ac, auth->authorizer);
3452                auth->authorizer = NULL;
3453        }
3454        if (!auth->authorizer) {
3455                int ret = ceph_auth_create_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3456                                                      auth);
3457                if (ret)
3458                        return ERR_PTR(ret);
3459        } else {
3460                int ret = ceph_auth_update_authorizer(ac, CEPH_ENTITY_TYPE_MDS,
3461                                                      auth);
3462                if (ret)
3463                        return ERR_PTR(ret);
3464        }
3465        *proto = ac->protocol;
3466
3467        return auth;
3468}
3469
3470
3471static int verify_authorizer_reply(struct ceph_connection *con, int len)
3472{
3473        struct ceph_mds_session *s = con->private;
3474        struct ceph_mds_client *mdsc = s->s_mdsc;
3475        struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3476
3477        return ceph_auth_verify_authorizer_reply(ac, s->s_auth.authorizer, len);
3478}
3479
3480static int invalidate_authorizer(struct ceph_connection *con)
3481{
3482        struct ceph_mds_session *s = con->private;
3483        struct ceph_mds_client *mdsc = s->s_mdsc;
3484        struct ceph_auth_client *ac = mdsc->fsc->client->monc.auth;
3485
3486        ceph_auth_invalidate_authorizer(ac, CEPH_ENTITY_TYPE_MDS);
3487
3488        return ceph_monc_validate_auth(&mdsc->fsc->client->monc);
3489}
3490
3491static struct ceph_msg *mds_alloc_msg(struct ceph_connection *con,
3492                                struct ceph_msg_header *hdr, int *skip)
3493{
3494        struct ceph_msg *msg;
3495        int type = (int) le16_to_cpu(hdr->type);
3496        int front_len = (int) le32_to_cpu(hdr->front_len);
3497
3498        if (con->in_msg)
3499                return con->in_msg;
3500
3501        *skip = 0;
3502        msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
3503        if (!msg) {
3504                pr_err("unable to allocate msg type %d len %d\n",
3505                       type, front_len);
3506                return NULL;
3507        }
3508
3509        return msg;
3510}
3511
3512static const struct ceph_connection_operations mds_con_ops = {
3513        .get = con_get,
3514        .put = con_put,
3515        .dispatch = dispatch,
3516        .get_authorizer = get_authorizer,
3517        .verify_authorizer_reply = verify_authorizer_reply,
3518        .invalidate_authorizer = invalidate_authorizer,
3519        .peer_reset = peer_reset,
3520        .alloc_msg = mds_alloc_msg,
3521};
3522
3523/* eof */
3524
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